We consent to the incorporation by reference in the Registration Statement (Form S-8) pertaining to the Amended and Restated Ionis Pharmaceuticals, Inc. 2011 Equity Incentive Plan and the Amended and Restated Ionis Pharmaceuticals, Inc. 2000 Employee Stock Purchase Plan, of our reports dated February 26, 2026, with respect to the consolidated financial statements of Ionis Pharmaceuticals, Inc. and the effectiveness of internal control over financial reporting of Ionis Pharmaceuticals, Inc. included in its Annual Report (Form 10-K) for the year ended December 31, 2025, filed with the Securities and Exchange Commission.