File No. 33-43846

811-00524

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

FORM N-1A

REGISTRATION STATEMENT UNDER THE SECURITIES ACT OF 1933[X]

Pre-Effective Amendment No.[__]

Post-Effective Amendment No. 237[X]

and/or

REGISTRATION STATEMENT UNDER THE INVESTMENT COMPANY ACT OF 1940[X]

Amendment No. 237[X]

(Check appropriate box or boxes.)

BNY Mellon Investment Funds III

(Exact Name of Registrant as Specified in Charter)

c/o BNY Mellon Investment Adviser, Inc.

240 Greenwich Street, New York, New York 10286

(Address of Principal Executive Offices) (Zip Code)

Registrant's Telephone Number, including Area Code: (212) 922-6400

Bennett A. MacDougall, Esq.

240 Greenwich Street

New York, New York 10286

(Name and Address of Agent for Service)

It is proposed that this filing will become effective (check appropriate box)

Ximmediately upon filing pursuant to paragraph (b)

_ on (date) pursuant to paragraph (b)

___ days after filing pursuant to paragraph (a)(1)

__on (date) pursuant to paragraph (a)(1)

____ days after filing pursuant to paragraph (a)(2)

__on (date) pursuant to paragraph (a)(2) of Rule 485

If appropriate, check the following box:

__this post-effective amendment designates a new effective date for a previously filed post-effective amendment.

The following post-effective amendment to the Registrant's Registration Statement on Form N-1A only affects the Registration Statement of the series below:

BNY Mellon High Yield Fund

SIGNATURES

Pursuant to the requirements of the Securities Act of 1933 and the Investment Company Act of 1940, the Registrant certifies that it meets all of the requirements of effectiveness of this Amendment to the Registration Statement pursuant to Rule 485(b) under the Securities Act of 1933 and has duly caused this Amendment to the Registration Statement to be signed on its behalf by the undersigned, duly authorized, in the City of New York, and State of New York on the 4th day of May, 2020.

BNY Mellon Investment Funds III

BY:	/s/ Renee LaRoche-Morris*
	Renee LaRoche-Morris, PRESIDENT

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

Signatures		Title	Date
/s/ Renee LaRoche-Morris*		President (Principal Executive Officer)	5/4/2020
Renee LaRoche-Morris
/s/ James Windels*		Treasurer (Principal Financial and Accounting Officer)	5/4/2020
James Windels
/s/ Joseph S. DiMartino*		Chairman of the Board	5/4/2020
Joseph S. DiMartino
/s/ Francine J. Bovich*		Board Member	5/4/2020
Francine J. Bovich
/s/ Andrew J. Donohue*		Board Member	5/4/2020
Andrew J. Donohue
/s/ Kenneth A. Himmel*		Board Member	5/4/2020
Kenneth A. Himmel
/s/ Stephen J. Lockwood*		Board Member	5/4/2020
Stephen J. Lockwood
/s/ Roslyn M. Watson*		Board Member	5/4/2020
Roslyn M. Watson
/s/ Benaree Pratt Wiley*		Board Member	5/4/2020
Benaree Pratt Wiley
*BY:	/s/ James Bitetto
	James Bitetto Attorney-in-Fact

INDEX OF EXHIBITS

Exhibits

EX-101.INS – Instance Document.

EX-101.SCH – Taxonomy.

EX-101.CAL – Calculation Linkbase.

EX-101.DEF – Definition Linkbase.

EX-101.LAB – Labels Linkbase.

EX-101.PRE – Presentation Linkbase.