The ability to control polymerizations via external stimuli has become a burgeoning field of research. Herein, we will demonstrate that polyethylene microstructure may be tailored via a redox-active olefin polymerization catalyst in conjunction with a photoreductant and visible light irradiation. The changes in polyethylene branching content are confirmed via¹H NMR analysis, gel permeation chromatography, and quantitative ¹³C NMR spectroscopy.