Exhibit 23.1

CONSENT OF INDEPENDENT REGISTERED PUBLIC ACCOUNTING FIRM

We hereby consent to the use in this Registration Statement on Form S-1 of SIGA Technologies, Inc. of our report dated March 4, 2016 relating to the financial statements and the effectiveness of internal control over financial reporting of SIGA Technologies, Inc., which appears in such Registration Statement. We also consent to the reference to us under the heading “Experts” in such Registration Statement.

/s/ PricewaterhouseCoopers LLP

PricewaterhouseCoopers LLP

New York, New York

September 19, 2016