A simple and efficient approach of C-S cross-coupling of a wide variety of (hetero)aryl thiols and (hetero)aryl halides under mild conditions, mostly at room temperature, catalyzed by well-defined singlet diradical Ni(II) catalysts bearing redox noninnocent ligands is reported. Taking advantage of ligand centered redox events, the high-energetic Ni(0)/Ni(II) or Ni(I)/Ni(III) redox steps were avoided in the catalytic cycle. The cooperative participation of both nickel and the coordinated ligands during oxidative addition/reductive elimination steps allowed us to perform the catalytic reactions under mild conditions.