Maskell was born in London. As a youth, he played football for Long Lane JFC as a full back. He first trained in acting at the Anna Scher Theatre in Islington, London, where he attended classes from the age of 11,[2] and studied at the Miskin Theatre, Dartford at North West Kent College from 1992. He later worked as a director at the Miskin Theatre.[3]
In 2021, Maskell played the titular and lead character in British gangster revenge film Bull, with Tamzin Outhwaite.[11]
Television
Maskell's first television appearance was in 1991 in the ITV police drama The Bill.[6] Between 1992 and 2002, he made a further five appearances on the show, portraying a different character each time. He has had one-off roles in a number of other popular British serial dramas such as Casualty, London's Burning, Soldier Soldier.[6] His most regular television roles have been in the 2005 comedy series Mike Bassett: Manager, in the comedy sketch show The Wrong Door, and in the 2013–2014 thriller drama action series Utopia. Since 2015, he has been a series regular in sci-fi thriller Humans. In 2019 Maskell played prime minister Winston Churchill in the series finale of Peaky Blinders.[6]
In 2022, Maskell played Detective Inspector Brent Hyatt in the ITV drama, Litvinenko, detailing the final days and subsequent murder investigation into the death of Russian defector Alexander Litvinenko.[6]