Popular in Northern Ireland for various sketches (including the trendy priest) in Dry Your Eyes, he had a feature role in a short film by Simon Fitzmaurice called The Sound of People. He followed that up with his feature film debut (as Jimmy Riley) in Closing the Ring (2007), directed by Richard Attenborough. Attenborough cast McCann in the film after seeing him in a stage production of A Clockwork Orange. McCann had a role in the film My Boy Jack (as Guardsman Bowe), about Rudyard Kipling and his son, who was killed in World War I.
In early 2010 he was shooting in Belfast for the music-comedy Killing Bono, a film released in April 2011 about the life of one of Bono's classmates who tries to make it in the music Business, only to have his failures and frustrations magnified by the continued rise of U2. McCann plays the supporting role of Bono. In 2011, McCann completed a principal role in Terry George's Whole Lotta Sole, He is currently working on a twelve part mini series drama chronicling the building of the Titanic and the story about the ship before it left on its maiden voyage.
In February 2011, Martin won the 2011 Irish Film and Television Academy Award for lead actor in a feature film. McCann was awarded this for his performance as Occi Byrne in Swansong produced by Zanzibar films.
In 2016, he voiced Bobby Sands in reenactments in the documentary film Bobby Sands: 66 Days, and he also starred in The Survivalist (film), as 'Survivalist'.
In 2017, actor Woody Harrelson cast Martin McCann in his directorial debut 'Lost In London'. This was the first 'live streamed' feature film direct to cinemas.
