<p>The phosphorylation of alkenes offers a diverse handle for obtaining organophosphoryls, but its regioselectivity still faces challenges, especially the radical Markovnikov hydrophosphorylation of alkenes. Herein, we develop a radical Markovnikov hydrophosphorylation of unactivated alkenes by a sequential reaction of (bis)homoallylic alcohols, Ph₂PCl, and water under visible light-driven triple catalysis. The protocol initiates from a Co-H species-mediated metal-hydride atom transfer, followed by a water-mediated radical-polar crossover phosphinite rearrangement. This reaction features mild reaction conditions, excellent regio-/stereoselectivity, and good natural products compatibility. The successful radical deuterophosphonation of olefins by using D₂O to replace H₂O further demonstrates the synthetic value of the protocol. This protocol not only broadens the mode of phosphinite rearrangement, but also provides a successful example for the radical activation of water and its three-atom splitting and utilization in organic conversion.</p>