Herein, we report an efficient and practical protocol for dehalocarboxylation of C(sp²)-halides with formate by the engagement of a CO₂ radical anion in a nickel-mediated bond-forming process. A wide variety of aryl iodides, aryl bromides, and alkenyl bromides bearing a diverse set of functional groups underwent the reaction smoothly through visible-light photoredox nickel dual catalysis. The synthesis of several ¹³C-labeled drug intermediates and the gram-scale synthesis of commercial drugs highlight the synthetic value of the approach in drug discovery settings.