Alkyl chlorides are common functional groups in synthetic organic chemistry. However, the engagement of unactivated alkyl chlorides, especially tertiary alkyl chlorides, in transition-metal-catalyzed C–C bond formation remains challenging. Herein, we describe the development of a Ti^III-catalyzed radical addition of 2° and 3° alkyl chlorides to electron-deficient alkenes. Mechanistic data are consistent with inner-sphere activation of the C–Cl bond featuring Ti^III-mediated Cl atom abstraction. Evidence suggests that the active Ti^III catalyst is generated from the Ti^IV precursor in a Lewis-acid-assisted electron transfer process.