The news of Farrell's inclusion was first made public on Sunday, Sept. 21, when the actor, 38, let slip that he is in the critically acclaimed program. "I'm doing the second series," he told the Irish paper The Sunday World. "I'm so excited," adding that he will shoot eight episodes over the course of four or five months.
Vaughn, 44, was added to the lineup as Farrell's costar. The two men replace season one actors Matthew McConaughey and Woody Harrelson.
Casting for the highly anticipated season two has been the subject of ongoing speculation, jokes, and memes, with many calling for HBO to include a female lead in the second season. Instead, the Winter's Tale actor and The Delivery Man star will be the focus of the second installment.
HBO also announced on Tuesday that The Fast and the Furious director Justin Lin will helm the first two episodes of the season, which focuses on "three police officers and a career criminal [who] must navigate a web of conspiracy in the aftermath of a murder."
Farrell will play a detective named Ray Velcoro, while Vaughn will take on the criminal role of Frank Semyon. The Emmy-winning show is rumored to return for its second season in mid-2015.
For access to all our exclusive celebrity videos and interviews – Subscribe on YouTube!