In 2012 Rayner starred as Aiden marsh on the television series Hunted. Since 2014 he has starred as Barry Al-Fayeed on the series Tyrant. He has starred in the movies RedMeansGo, Love and Other Disasters, Straightheads, Steel Trap, The Task, and Tracers. Rayner has also appeared in episodes of the TV series At Home with the Braithwaites, Making Waves, Vincent, Sensitive Skin, Doctor Who, Waking the Dead, Undercovers, and Miranda. He is in a relationship with actress Lucy Brown and has dual citizenship in the United States and the United Kingdom.