As filed with the Securities and Exchange Commission on March 8, 2018
================================================================================
                                                    1933 Act File No. 333-217581
                                                     1940 Act File No. 811-22738


                    U.S. SECURITIES AND EXCHANGE COMMISSION
                             Washington, D.C. 20549

                                    FORM N-2

(Check appropriate box or boxes)

[X]  REGISTRATION STATEMENT UNDER THE SECURITIES ACT OF 1933
[ ]  Pre-Effective Amendment No. __
[X]  Post-Effective Amendment No. 4

and

[X]  REGISTRATION STATEMENT UNDER THE INVESTMENT COMPANY ACT OF 1940
[X]  Amendment No. 11

                     First Trust MLP and Energy Income Fund
         Exact Name of Registrant as Specified in Declaration of Trust


            10 Westport Road, Suite C101a, Wilton, Connecticut 06897
 Address of Principal Executive Offices (Number, Street, City, State, Zip Code)


                                 (630) 765-8000
               Registrant's Telephone Number, including Area Code


                             W. Scott Jardine, Esq.
                          First Trust Portfolios L.P.
                       120 East Liberty Drive, Suite 400
                            Wheaton, Illinois 60187

 Name and Address (Number, Street, City, State, Zip Code) of Agent for Service


                          Copies of Communications to:

                               Eric F. Fess, Esq.
                             Chapman and Cutler LLP
                             111 West Monroe Street
                            Chicago, Illinois 60603

Approximate Date of Proposed Public Offering: From time to time after the
effective date of this Registration Statement

---------------

     If any of the securities being registered on this form are offered on a
delayed or continuous basis in reliance on Rule 415 under the Securities Act of
1933, other than securities offered in connection with a dividend reinvestment
plan, check the following box. [X]

     This Post-Effective Amendment No. 4 will become effective immediately upon
filing pursuant to Rule 462(d) under the Securities Act of 1933.





EXPLANATORY NOTE

     This Post-Effective Amendment No. 4 to the Registration Statement on Form
N-2 (File No. 333-217581) of First Trust MLP and Energy Income Fund (the
"Registration Statement") is being filed pursuant to Rule 462(d) under the
Securities Act of 1933, as amended (the "Securities Act"), solely for the
purpose of filing exhibits to the Registration Statement. Accordingly, this
Post-Effective Amendment No. 4 consists only of a facing page, this explanatory
note and Part C of the Registration Statement on Form N-2 setting forth the
exhibits to the Registration Statement. This Post-Effective Amendment No. 4 does
not modify any other part of the Registration Statement.





PART C - OTHER INFORMATION

Item 25: Financial Statements and Exhibits

1.    Financial Statements:

     The Registrant's audited financial statements, notes to the financial
statements and the report of independent public accounting firm thereon have
been incorporated into Part B of the Registration Statement by reference to
Registrant's Annual Report for the fiscal year ended October 31, 2017 contained
in its Form N-CSR, as described in the statement of additional information.

2.    Exhibits:

a.    Declaration of Trust dated August 15, 2012. (1)

a.2   Amendment to Declaration of Trust dated October 2, 2012. (3)

a.3   Amendment to Declaration of Trust dated October 15, 2012 (3)

a.4   Amendment to Declaration of Trust dated November 8, 2012. (4)

b.1   By-Laws of Fund. (2)

b.2   Amended By-Laws of Fund. (4)

c.    None.

d.    None.

e.    Terms and Conditions of the Dividend Reinvestment Plan. (4)

f.    None.

g.1   Form of Investment Management Agreement between Registrant and First Trust
      Advisors L.P. (4)

g.2   Form of Investment Sub-Advisory Agreement between Registrant, First Trust
      Advisors L.P. and Energy Income Partners, LLC. (4)

h.1   Form of Underwriting Agreement.*

h.2   Form of Sales Agreement. (6)

i.    None.

j.    Form of Custody Agreement between Registrant and Fund Custodian. (4)





k.1   Form of Service Agreement for Transfer Agent Services between Registrant
      and Fund Transfer Agent. (4)

k.2   Form of Administration and Accounting Services Agreement. (4)

k.3   Committed Lending Agreement dated November 1, 2013. (6)

l.1   Opinion and consent of Chapman and Cutler LLP. (6)

l.2   Opinion and consent of Chapman and Cutler LLP.**

l.3   Opinion and consent of Morgan, Lewis & Bockius LLP. (6)

l.4   Opinion and consent of Morgan, Lewis & Bockius LLP.**

m.    None.

n.    Consent of Independent Registered Public Accounting Firm.**

o.    None.

p.    Subscription Agreement between Registrant and First Trust Advisors
      L.P. (4)

q.    None.

r.1   Code of Ethics of Registrant. (4)

r.2   Code of Ethics of First Trust Portfolios L.P. (4)

r.3   Code of Ethics of First Trust Advisors L.P. (4)

r.4.  Code of Ethics of Energy Income Partners, LLC. (4)

s.    Powers of Attorney. (5)

----------------------------

(1)   Filed on August 17, 2012 as Exhibit a. to Registrant's Registration
      Statement on Form N-2 (File No. 333-183396) and incorporated herein by
      reference.

(2)   Filed on October 4, 2012 in Pre-Effective Amendment No. 1 to Registrant's
      Registration Statement on Form N-2 (File No. 333-183396) and incorporated
      herein by reference.

(3)   Filed October 23, 2012 in Pre-Effective Amendment No. 2 to Registrant's
      Registration Statement on Form N-2 (File No. 333-183396) and incorporated
      herein by reference.





(4)   Filed on November 27, 2012 in Pre-Effective Amendment No. 3 to
      Registrant's Registration Statement on Form N-2 (File No. 333-183396) and
      incorporated herein by reference.

(5)   Filed on May 2, 2017 as Exhibit s. to Registrant's Registration Statement
      on Form N-2 (File No. 333-217581) and incorporated herein by reference.

(6)   Filed on June 19, 2017 in Post-Effective Amendment No. 1 to Registrant's
      Registration Statement on Form N-2 (File No. 333-217581) and incorporated
      herein by reference.

*     To be filed by amendment.

**    Filed herewith.

--------------------------------------------------------------------------------

Item 26: Marketing Arrangements

     The information contained under the heading "Plan of Distribution"
contained in Registrant's Prospectus, filed as Part A of Registrant's
Registration Statement on March 1, 2018 is incorporated by reference herein.

     The information contained in the Sales Agreement among the Registrant,
First Trust Advisors L.P., Energy Income Partners, LLC and JonesTrading
Institutional Services LLC for the Registrant's common shares of beneficial
interest, filed on June 19, 2017 as Exhibit h.2 to Post-Effective Amendment No.
1 to Registrant's Registration Statement on Form N-2 (File No. 333-217581), is
incorporated by reference herein.





Item 27: Other Expenses of Issuance and Distribution

---------------------------------------------------------- --------------------
Securities and Exchange Commission Fees                    $ 24,368
---------------------------------------------------------- --------------------
Financial Industry Regulatory Authority, Inc. Fees         $ 31,536
---------------------------------------------------------- --------------------
Printing and Engraving Expenses                            $ 19,500
---------------------------------------------------------- --------------------
Legal Fees                                                 $228,950
---------------------------------------------------------- --------------------
Listing Fees                                               $  5,000
---------------------------------------------------------- --------------------
Accounting Expenses                                        $ 35,500
---------------------------------------------------------- --------------------
Blue Sky Filing Fees and Expenses                          $     --
---------------------------------------------------------- --------------------
Miscellaneous Expenses                                     $    120
---------------------------------------------------------- --------------------
Total                                                      $344,974
---------------------------------------------------------- --------------------


Item 28: Persons Controlled by or under Common Control with Registrant

    Not applicable.


Item 29:  Number of Holders of Securities

    At December 31, 2017

--------------------------------------------  ---------------------------------
Title of Class                                Number of Record Holders
--------------------------------------------  ---------------------------------
Common Shares, $0.01 par value                26,618
--------------------------------------------  ---------------------------------





Item 30: Indemnification

Section 9.5 of the Registrant's Declaration of Trust provides as follows:

     Indemnification and Advancement of Expenses. Subject to the exceptions and
limitations contained in this Section 9.5, every person who is, or has been, a
Trustee, officer or employee of the Trust, including persons who serve at the
request of the Trust as directors, trustees, officers, employees or agents of
another organization in which the Trust has an interest as a shareholder,
creditor or otherwise (hereinafter referred to as a "Covered Person"), shall be
indemnified by the Trust to the fullest extent permitted by law against
liability and against all expenses reasonably incurred or paid by him in
connection with any claim, action, suit or proceeding in which he becomes
involved as a party or otherwise by virtue of his being or having been such a
Trustee, director, officer, employee or agent and against amounts paid or
incurred by him in settlement thereof.

     No indemnification shall be provided hereunder to a Covered Person to the
extent such indemnification is prohibited by applicable federal law.

     The rights of indemnification herein provided may be insured against by
policies maintained by the Trust, shall be severable, shall not affect any other
rights to which any Covered Person may now or hereafter be entitled, shall
continue as to a person who has ceased to be such a Covered Person and shall
inure to the benefit of the heirs, executors and administrators of such a
person.

     Subject to applicable federal law, expenses of preparation and presentation
of a defense to any claim, action, suit or proceeding subject to a claim for
indemnification under this Section 9.5 shall be advanced by the Trust prior to
final disposition thereof upon receipt of an undertaking by or on behalf of the
recipient to repay such amount if it is ultimately determined that he is not
entitled to indemnification under this Section 9.5.

     To the extent that any determination is required to be made as to whether a
Covered Person engaged in conduct for which indemnification is not provided as
described herein, or as to whether there is reason to believe that a Covered
Person ultimately will be found entitled to indemnification, the Person or
Persons making the determination shall afford the Covered Person a rebuttable
presumption that the Covered Person has not engaged in such conduct and that
there is reason to believe that the Covered Person ultimately will be found
entitled to indemnification.

     As used in this Section 9.5, the words "claim," "action," "suit" or
"proceeding" shall apply to all claims, demands, actions, suits, investigations,
regulatory inquiries, proceedings or any other occurrence of a similar nature,
whether actual or threatened and whether civil, criminal, administrative or
other, including appeals, and the words "liability" and "expenses" shall include
without limitation, attorneys' fees, costs, judgments, amounts paid in
settlement, fines, penalties and other liabilities.

Section 9 of the Form of Sales Agreement previously filed as Exhibit h.2 to this
Registration Statement provides for each of the parties thereto, including the
Registrant and the underwriters, to indemnify the others, their Trustees,
directors, certain of their officers, Trustees, directors and persons who
control them against certain liabilities in connection with the offering
described herein, including liabilities under the federal securities laws.

Insofar as indemnification for liability arising under the Securities Act of
1933, as amended (the "1933 Act"), may be available to Trustees, officers and
controlling persons of the Registrant pursuant to the foregoing provisions, or
otherwise, the Registrant has been advised that in the opinion of the SEC such
indemnification is against public policy as expressed in the 1933 Act and is,
therefore, unenforceable. In the event that a claim for indemnification against
such liabilities (other than the payment by the Registrant's expenses incurred
or paid by a Trustee, officer or controlling person of the Registrant in the
successful defense of any action, suit or proceeding) is asserted by such
Trustee, officer or controlling person in connection with the securities being
registered, the Registrant will, unless in the opinion of its counsel the matter
has been settled by controlling precedent, submit to a court of appropriate
jurisdiction the question whether such indemnification by it is against public
policy as expressed in the 1933 Act and will be governed by the final
adjudication of such issue.


Item 31: Business and Other Connections of Investment Advisors

The information in the Statement of Additional Information under the captions
"Management of the Fund - Trustees and Officers" and "Sub-Advisor," and the Form
ADV of Energy Income Partners, LLC (File No. 801-66907) filed with the
Commission are hereby incorporated by reference.


Item 32: Location of Accounts and Records.

First Trust Advisors L.P. maintains the Declaration of Trust, By-Laws, minutes
of trustees and shareholders meetings and contracts of the Registrant, all
advisory material of the investment adviser, all general and subsidiary ledgers,
journals, trial balances, records of all portfolio purchases and sales, and all
other required records.


Item 33: Management Services

Not applicable.


Item 34: Undertakings

1.    Not applicable.

2.    Not applicable.

3.    Not applicable.

4.    The Registrant undertakes (a) to file, during any period in which offers
      or sales are being made, a post-effective amendment to this Registration
      Statement:

(1)   to include any prospectus required by Section 10(a)(3) of the Securities
      Act of 1933;

(2)   to reflect in the prospectus any facts or events arising after the
      effective date of the registration statement (or the most recent
      post-effective amendment thereof) which, individually or in the aggregate,
      represent a fundamental change in the information set forth in the
      registration statement; and

(3)   to include any material information with respect to the plan of
      distribution not previously disclosed in the registration statement or any
      material change to such information in the registration statement;

(b)   that, for the purpose of determining liability under the Securities Act of
      1933, each such post-effective amendment shall be deemed to be a new
      registration statement relating to the securities offered therein, and the
      offering of those securities at that time shall be deemed to be the
      initial bona fide offering thereof; and

(c)   to remove from registration by means of a post-effective amendment any of
      the securities being registered which remain unsold at the termination of
      the offering;

(d)   that, for the purpose of determining liability under the Securities Act of
      1933 to any purchaser, if the Registrant is subject to Rule 430C; each
      prospectus filed pursuant to Rule 497(b), (c), (d) or (e) under the
      Securities Act of 1933, shall be deemed to be part of and included in this
      Registration Statement as of the date it is first used after
      effectiveness. Provided, however, that no statement made in this
      Registration Statement or prospectus that is part of this registration
      statement or made in a document incorporated or deemed incorporated by
      reference into this registration statement or prospectus that is art of
      this registration statement will, as to a purchaser with a time of
      contract of sale prior to such first use, supercede or modify any
      statement that was made in this registration statement or prospectus that
      was part of this registration statement or made in any such document
      immediately prior to such date of first use;

(e)   that for the purpose of determining liability of the Registrant under the
      Securities Act of 1933 to any purchaser in the initial distribution of
      securities:

      The undersigned Registrant undertakes that in a primary offering of
      securities of the undersigned Registrant pursuant to this registration
      statement, regardless of the underwriting method used to sell the
      securities to the purchaser, if the securities are offered or sold to such
      purchaser by means of any of the following communications, the undersigned
      Registrant will be a seller to the purchaser and will be considered to
      offer or sell such securities to the purchaser:

(1)   any preliminary prospectus or prospectus of the undersigned Registrant
      relating to the offering required to be filed pursuant to Rule 497 under
      the Securities Act of 1933;

(2)   the portion of any advertisement pursuant to Rule 482 under the Securities
      Act of 1933 relating to the offering containing material information about
      the undersigned Registrant or its securities provided by or on behalf of
      the undersigned Registrant; and

(3)   any other communication that is an offer in the offering made by the
      undersigned Registrant to the purchaser.

5.    The Registrant undertakes that:

a.    For purposes of determining any liability under the Securities Act of
      1933, the information omitted from the form of prospectus filed as part of
      a registration statement in reliance upon Rule 430A and contained in the
      form of prospectus filed by the Registrant under Rule 497(h) under the
      Securities Act of 1933 shall be deemed to be part of the Registration
      Statement as of the time it was declared effective; and

b.    For the purpose of determining any liability under the Securities Act of
      1933, each post-effective amendment that contains a form of prospectus
      shall be deemed to be a new registration statement relating to the
      securities offered therein, and the offering of the securities at that
      time shall be deemed to be the initial bona fide offering thereof.

6.    The Registrant undertakes to send by first class mail or other means
      designed to ensure equally prompt delivery, within two business days of
      receipt of a written or oral request, any Statement of Additional
      Information.

7.    Upon each issuance of securities pursuant to this Registration Statement,
      the Registrant undertakes to file a form of prospectus and/or prospectus
      supplement pursuant to Rule 497 and a post-effective amendment to the
      extent required by the Securities Act of 1933 and the rules and
      regulations thereunder, including, but not limited to a post-effective
      amendment pursuant to Rule 462(c) or Rule 462(d) under the Securities Act
      of 1933.





                                   SIGNATURES

     Pursuant to the requirements of the Securities Act of 1933 and the
Investment Company Act of 1940, the Registrant has duly caused this Registration
Statement to be signed on its behalf by the undersigned, thereunto duly
authorized, in this City of Wheaton, and State of Illinois, on the 8th day of
March, 2018.

                                     FIRST TRUST MLP AND ENERGY INCOME FUND


                                     By: /s/ James M. Dykas
                                         ------------------------------------
                                         James M. Dykas, President and
                                         Chief Executive Officer


      Pursuant to the requirements of the Securities Act of 1933, this
Registration Statement has been signed below by the following persons in the
capacities and on the date indicated.

---------------------  ---------------------------------  --------------------
Signature              Title                              Date
---------------------  ---------------------------------  --------------------

/s/ James M. Dykas     President and Chief Executive      March 8, 2018
--------------------   Officer (Principal
 James M. Dykas        Executive Officer)

---------------------  ---------------------------------  --------------------

/s/ Donald P. Swade    Chief Financial Officer, Chief     March 8, 2018
--------------------   Accounting Officer and
 Donald P. Swade       Treasurer (Principal Financial
                       and Accounting Officer)


----------------------- ------------------------- ----------------------------
James A. Bowen(1)       Chairman of the Board    )
                        and Trustee              )
----------------------- ------------------------ )
Richard E. Erickson(1)  Trustee                  ) By:  /s/ W. Scott Jardine
----------------------- ------------------------ )      ---------------------
Thomas R. Kadlec(1)     Trustee                  )      W. Scott Jardine
----------------------- ------------------------ )      Attorney-In-Fact
Robert F. Keith(1)      Trustee                  )      March 8, 2018
----------------------- ------------------------ )
Niel B. Nielson(1)      Trustee                  )
----------------------- ------------------------- ----------------------------

---------------

(1) Original powers of attorney authorizing W. Scott Jardine, James M. Dykas,
Eric F. Fess and Kristi A. Maher to execute Registrant's Registration Statement,
and Amendments thereto, for each of the trustees of the Registrant on whose
behalf this Registration Statement is filed, were previously executed and filed
on May 2, 2017 as an Exhibit to the Registrant's Registration Statement on Form
N-2 (File No. 333-217581).





                               INDEX TO EXHIBITS


l.2   Opinion and consent of Chapman and Cutler LLP.

l.4   Opinion and consent of Morgan, Lewis & Bockius LLP.

n.    Consent of Independent Registered Public Accounting Firm.