UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

FORM 8-A

For Registration of Certain Classes of Securities

Pursuant to Section 12(b) or (g) of

the Securities Exchange Act of 1934

ULTRAGENYX PHARMACEUTICAL INC.

(Exact name of registrant as specified in its charter)

Delaware	27-2546083
(State of Incorporation)	(I.R.S. Employer Identification No.)
60 Leveroni Court, Novato, CA	94949
(Address of principal executive offices)	(Zip Code)

Securities to be registered pursuant to Section 12(b) of the Act:

Title of each class to be so registered	Name of each exchange on which each class is to be registered
Common Stock, par value $0.001 per share	The NASDAQ Stock Market LLC

If this form relates to the registration of a class of securities pursuant to Section 12(b) of the Exchange Act and is effective pursuant to General Instruction A.(c), check the following box.   x

If this form relates to the registration of a class of securities pursuant to Section 12(g) of the Exchange Act and is effective pursuant to General Instruction A.(d), check the following box.   ¨

Securities Act registration statement file number to which this form relates (if applicable):

333-192244

Securities to be registered pursuant to Section 12(g) of the Act:

None

Item 1. Description of Registrant’s Securities to be Registered

Ultragenyx Pharmaceutical Inc. (the “Registrant”) hereby incorporates by reference the description of its common stock, par value $0.001 per share, to be registered hereunder, contained under the heading “Description of Capital Stock” in the prospectus included in the Registrant’s Registration Statement on Form S-1 (File No. 333-192244), as originally filed with the Securities and Exchange Commission (the “Commission”) on November 8, 2013, as amended (the “Registration Statement”), and in the prospectus to be subsequently filed by the Registrant with the Commission pursuant to Rule 424(b) under the Securities Act of 1933, as amended, which prospectus shall be deemed to be incorporated by reference herein.

Item 2. Exhibits

Pursuant to the Instructions as to Form 8-A exhibits, no exhibits are required to be filed because no other securities of the Registrant are registered on The NASDAQ Stock Market LLC and the securities registered hereby are not being registered pursuant to Section 12(g) of the Securities Exchange Act, as amended.

Signature

Pursuant to the requirements of Section 12 of the Securities Exchange Act of 1934, the Registrant has duly caused this registration statement to be signed on its behalf by the undersigned, thereto duly authorized.

Date: January 24, 2014	ULTRAGENYX PHARMACEUTICAL INC.
	By:	/s/ EMIL D. KAKKIS
		Emil D. Kakkis, M.D., Ph.D.
		President and Chief Executive Officer