Exhibit 23.1

CONSENT OF INDEPENDENT REGISTERED PUBLIC ACCOUNTING FIRM

We consent to the use in this Registration Statement on Form S-1 of our report dated March 7, 2014, relating to the consolidated financial statements of Cerulean Pharma Inc. (which report expresses an unqualified opinion and includes an explanatory paragraph relating to the Company’s ability to continue as a going concern) appearing in the Prospectus, which is a part of this Registration Statement.

We also consent to the reference to us under the heading “Experts” in such Prospectus.

/s/ Deloitte & Touche LLP

Boston, Massachusetts

March 7, 2014