Photoinduced hydroarylation of alkenes is an appealing synthetic strategy for arene functionalization. Herein, we demonstrated that aryl radicals generated from electron‐deficient aryl chlorides/bromides could be trapped by an array of terminal/internal aryl alkenes in the presence of Pt(O^N^C^N) under visible‐light (410 nm) irradiation, affording anti‐Markovnikov hydroarylated compounds in up to 95 % yield. Besides, a protocol for Pt(O^N^C^N)‐catalyzed intramolecular photocyclization of acrylanilides to give structurally diverse 3,4‐dihydroquinolinones has been developed. In the presence of luminescent Pt(O^N^C^N) complexes under visible light (410 nm) irradiation, aryl radicals derived from reductive aryl‐chloride/bromide bond cleavage were trapped by aryl alkenes and afforded a series of anti‐Markovnikov hydroarylated compounds. Pt(O^N^C^N)‐catalyzed intramolecular photocyclization of acrylanilides gives structurally diverse 3,4‐dihydroquinolinones.