Post-Effective Amendment to Post-Effective Amendment by Investment Company (Form 485BXT)

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As filed with the Securities and Exchange Commission on December 16, 2025 Securities Act File No. 333-207814 Investment Company Act File No. 811-23112	OMB Number: 3235-0307 Expires: July 31, 2027 Estimated average burden hours per response 297.7

UNITED STATES

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. 79	[X]
		and/or
REGISTRATION STATEMENT UNDER THE INVESTMENT COMPANY ACT OF 1940		[X]
	Amendment No. 80

(Check appropriate box or boxes.)

JANUS DETROIT STREET TRUST

(Exact Name of Registrant as Specified in Charter)

151 Detroit Street, Denver, Colorado 80206-4805

(Address of Principal Executive Offices) (Zip Code)

Registrant's Telephone Number, including Area Code: 303-333-3863

Cara Owen

151 Detroit Street

Denver, Colorado 80206-4805

(Name and Address of Agent for Service)

With Copies to:

Eric S. Purple

Stradley Ronon Stevens & Young, LLP

2000 K Street, N.W., Suite 700
Washington, D.C. 20006

Approximate Date of Proposed Public Offering: As soon as practicable after the effective date of this Registration Statement.

It is proposed that this filing will become effective: (check appropriate box)
	[ ]	immediately upon filing pursuant to paragraph (b)
	[X]	on January 16, 2026 at 12:01am Mountain Time pursuant to paragraph (b)
	[ ]	60 days after filing pursuant to paragraph (a)(1)
	[ ]	on _________ pursuant to paragraph (a)(1)
	[ ]	75 days after filing pursuant to paragraph (a)(2)
	[ ]	on _________ pursuant to paragraph (a)(2) of rule 485
If appropriate, check the following box:
	[X]	this post-effective amendment designates a new effective date for a previously filed post-effective amendment.

EXPLANATORY NOTE

Designation of New Effective Date for Previously Filed Amendment

Post-Effective Amendment No. 71 under the Securities Act of 1933, as amended (the "1933 Act"), and Amendment No. 72 under the Investment Company Act of 1940, as amended (the "1940 Act"), was filed with the Commission pursuant to paragraph (a)(2) of Rule 485 on August 26, 2025 to establish Janus Henderson Residential Mortgage Credit ETF, a new series of the Registrant (the "Amendment"), and pursuant to that paragraph would become effective on November 10, 2025. Post-Effective Amendment No. 74 under the 1933 Act and Amendment No. 75 under the 1940 Act was filed pursuant to Rule 485(b) (1)(iii) on November 7, 2025, designating November 17, 2025, as a new effective date for the Amendment. Post-Effective Amendment No. 77 under the 1933 Act and Amendment No. 78 under the 1940 Act was filed pursuant to Rule 485(b)(1)(iii) on November 14, 2025, designating December 17, 2025 as a new effective date for the Amendment.

This Post-Effective Amendment No. 79 under the 1933 Act and Amendment No. 80 under the 1940 Act is filed pursuant to Rule 485(b)(1)(iii) under the 1933 Act for the sole purpose of designating January 16, 2026 as the new date upon which the Amendment shall become effective.

This Post-Effective Amendment No. 79 incorporates by reference the information contained in Parts A, B, and C of the Post-Effective Amendment No. 71, which was filed on August 26, 2025.

The Registrant is a series fund with multiple series currently established. This Post-Effective Amendment No. 79 is not intended to update or amend the prospectuses or statements of additional information of any series except as described above.

SIGNATURES

Pursuant to the requirements of the Securities Act of 1933, as amended, and the Investment Company Act of 1940, as amended, the Registrant certifies that it meets all of the requirements for effectiveness of this Amendment to its Registration Statement pursuant to Rule 485(b)(1)(iii) under the Securities Act of 1933, as amended, and has duly caused this Post-Effective Amendment to its Registration Statement to be signed on its behalf by the undersigned, thereto duly authorized, in the City of Denver, and State of Colorado, on the 16^th day of December, 2025.

JANUS DETROIT STREET TRUST

By:	/s/ Nicholas Cherney
	Nicholas Cherney, President and Chief Executive Officer

Pursuant to the requirements of the Securities Act of 1933, as amended, this Registration Statement has been signed below by the following person(s) in the capacities and on the dates indicated.

Signature		Title		Date
/s/ Nicholas Cherney		President and Chief Executive Officer		December 16, 2025
Nicholas Cherney		(Principal Executive Officer)
/s/ Jesper Nergaard		Vice President, Chief Financial Officer, Treasurer, and Principal Accounting Officer (Principal Financial Officer and		December 16, 2025
Jesper Nergaard		Principal Accounting Officer)
Clifford J. Weber*		Chairman and Trustee		December 16, 2025
Clifford J. Weber
Gregory R. Trinks*		Trustee		December 16, 2025
Gregory R. Trinks
Maureen T. Upton*		Trustee		December 16, 2025
Maureen T. Upton
Jeffrey B. Weeden*		Trustee		December 16, 2025
Jeffrey B. Weeden

/s/ Jesper Nergaard
*By:	Jesper Nergaard
	Attorney-in-Fact

*	Pursuant to Powers of Attorney, dated October 24, 2024, is incorporated herein by reference as Exhibit (q)(1) to Post-Effective Amendment No. 61 to the Trust's Registration Statement, filed on Form N-1A with the SEC on November 8, 2024.

[ Janus Henderson Letterhead ]

December 16, 2025

EDGAR Operations Branch

Securities and Exchange Commission

Division of Investment Management

100 F Street, N.E.

Washington, D.C. 20549-0505

Re:	JANUS DETROIT STREET TRUST (the "Registrant")
	1933 Act File No. 333-207814
	1940 Act File No. 811-23112

Dear Sir or Madam:

On behalf of the Registrant, enclosed please find Post-Effective Amendment No. 79 and Amendment No. 80 under the Securities Act of 1933, as amended (the "1933 Act"), and the Investment Company Act of 1940, as amended, respectively, to the Registrant's Registration Statement on Form N-1A (the "Amendment"). The Registrant is filing the Amendment pursuant to Rule 485(b)(1)(iii) under the 1933 Act to designate a new effective date upon which the Amendment shall be effective.

As indicated on the facing page of the Amendment, the Registrant has specified that the Amendment is to become effective on January 16, 2026, pursuant to Rule 485(b) under the 1933 Act. This Amendment incorporates by reference the information contained in Parts A, B, and C of Post-Effective Amendment No. 71 to the Registrant's Registration Statement filed on August 26, 2025.

Pursuant to Rule 485(b)(4) of Regulation C under the 1933 Act, I hereby confirm that the Amendment does not contain disclosures that would render it ineligible to become effective under Rule 485(b).

If you have any questions regarding this filing, please call me at (303) 336-7903.

Respectfully,

/s/ Cara Owen
Cara Owen, Esq.
Vice President, Secretary, and Chief Legal Officer of the Registrant

Enclosures (via EDGAR)

cc:	Eric S. Purple, Esq.
	Jay Mensah, Esq.