March 22, 2024

Securities and Exchange Commission

100 F Street, N.E.

Washington, DC 20549-8626

Re:	American Century ETF Trust (the “Registrant”)
	1933 Act File No. 333-221045, Post-Effective Amendment No. 87 and
	1940 Act File No. 811-23305, Amendment No. 89 (collectively, the “Amendment”)

Ladies and Gentlemen:

Pursuant to Section 101(a) of Regulation S-T and Rule 485(a) under the Securities Act of 1933, the aforementioned Registrant hereby submits for filing the following Amendment to the Registration Statement on Form N‑1A.

The principal purposes of this Amendment are to: (i) add two new series of the Registrant, American Century California Municipal Bond ETF and Avantis U.S. Small Cap Equity Fund, and (ii) make certain other nonmaterial changes deemed appropriate by the Registrant.

If there are any questions or comments regarding this filing, please contact the undersigned at (816) 340-3267.

Sincerely,

/s/ Evan C. Johnson

Evan C. Johnson

Assistant Secretary

American Century Investments
P.O. Box 410141, 4500 Main Street	1-800-345-2021 or 816-531-5575
Kansas City, MO 64141-0141	www.americancentury.com