Exhibit 23.1

Consent of Independent Registered Public Accounting Firm

We consent to the incorporation by reference in this Registration Statement on Form S-8 of our reports dated February 12, 2025 relating to the consolidated financial statements of Sun Life Financial Inc. (the “Company”) and the effectiveness of the Company’s internal control over financial reporting appearing in the Annual Report on Form 40-F for the year ended December 31, 2024.

/s/ Deloitte LLP

Chartered Professional Accountants

Licensed Public Accountants

Toronto, Canada

February 13, 2025