A photoinduced catalytic C(sp3)-H alkylation of benzylic fluorides is developed. The use of zwitterionic 1,2,3-triazolium amidate as a hydrogen-atom transfer catalyst is uniquely effective for promoting this transformation. The combination of C-H alkylation with subsequent displacement of the C-F bond enables 1,1-difunctionalization of benzylic fluorides, providing rapid access to an array of functionalized molecular entities.