Exhibit 5.1

		ROPES & GRAY LLP
		PRUDENTIAL TOWER
		800 BOYLSTON STREET
		BOSTON, MA 02199-3600
		WWW.ROPESGRAY.COM

January 5, 2012

Synageva BioPharma Corp.

128 Spring Street, Suite 520

Lexington, MA 02421

Ladies and Gentlemen:

This opinion is furnished to you in connection with the above-referenced registration statement (the “Registration Statement”), the base prospectus dated December 20, 2011 (the “Base Prospectus”), the preliminary prospectus supplement dated January 4, 2012 (the “Preliminary Prospectus”) and the prospectus supplement dated January 5, 2012 (collectively with the Base Prospectus and the Preliminary Prospectus, the “Prospectus”). The Prospectus relates to the offering by Synageva BioPharma Corp. (the “Company”) of 3,108,057 shares (the “Shares”) of the Company’s common stock, par value $0.001 per share (the “Common Stock”). The Shares are covered by the Registration Statement. We understand that the Shares are to be offered and sold in the manner described in the Prospectus.

We have acted as counsel for the Company in connection with the Shares. For purposes of this opinion, we have examined and relied upon such documents, records, certificates and other instruments as we have deemed necessary.

The opinions expressed below are limited to the Delaware General Corporation Law, including the applicable provisions of the Delaware Constitution and the reported cases interpreting those laws.

Based upon and subject to the foregoing, we are of the opinion that the Shares have been duly authorized and when sold as described in the Prospectus, will be validly issued, fully paid and non-assessable.

We hereby consent to your filing this opinion as an exhibit to a Current Report on Form 8-K to be incorporated by reference in the Registration Statement and to the use of our name under the caption “Legal Matters” in the Prospectus contained therein. Our consent shall not be deemed an admission that we are experts whose consent is required under Section 7 of the Securities Act of 1933, as amended, or the rules and regulations of the Securities and Exchange Commission thereunder.

This opinion may be used only in connection with the offer and sale of the Shares while the Registration Statement remains effective.