John Allen McDorman IV is an American actor. On television, he headlined the CBS comedy-drama Limitless (2015-2016) and was the male lead of the sitcoms Are You There, Chelsea? (2012) and Manhattan Love Story (2014). He was also a series regular on the ABC Family comedy-drama Greek (2007-2011), the fourth season of the Showtime comedy-drama Shameless (2014), the revival of the CBS sitcom Murphy Brown (2018), and the Disney+ historical drama The Right Stuff (2020) as Alan Shepard.