There's a reason Tracker is TV's biggest show - and it all has to do with leading man Justin Hartley. Before introducing Us to Colter Shaw, Hartley got his start on soap operas, including Passions and Young and the Restless. He then moved on to Smallville, Revenge and Mistresses ahead of his fan-favorite role as Kevin Pearson on NBC's This Is Us. Hartley walked away from the hit series with three nominations for the Critics' Choice Television Awards and ultimately branched out with movie roles in A Bad Moms Christmas, Senior Year, The Noel Diary and more.