We have developed a novel system for C(sp 2 )-C(sp 3 ) CEC reactions of aryl and alkyl halides. Our system uses a Ni and Co dual catalytic platform in tandem with a relatively weak homogenous reductant to ensure that the key LNi II (Ar)X intermediate undergoes on-cycle reactions. Our system is able to efficiently couple a wide a range of substrates including heteroaryl halides, di-ortho-substituted aryl iodides, drug-like aryl halides and functionally diverse alkyl halides, all of which are rarely compatible with traditional methods for C(sp 2 )-C(sp 3 ) CEC.