In 2014, Martin won an Emmy Award for Outstanding Supporting Actor in a Miniseries or Movie playing John Watson on Sherlock: His Last Vow.
Martin is listed in the Performance Department Alumni of the Central School of Speech and Drama.
Martin was a successful junior squash player at county level. He was on the British national squash team until he was fourteen.
Martin does not have a drivers' license.
Martin is the cousin of stand-up comic, Ben Norris.
Martin and girlfriend, Amanda, have a miniature wire-haired dachshund named Archie.
Martin is the son of Philomena and Geoffrey Freeman. He has four siblings. One brother, Jamie, is a musician and website designer. His older brother, Tim, was in the eighties pop group 'Frazier Chorus'.
Martin studied at the Central School of Speech and Drama.
Martin's long-time girlfriend is actress Amanda Abbington. 
Martin: (on girls throwing themselves at him while his girlfriend is present) She's not very keen on that and neither am I. It is so disrespectful to the woman who is there. I haven't had it that badly, I've had it marginally. It's just so shallow. You know why people are doing it. It's not because I've discovered a cure for cancer, it's because they've seen me on the telly, which is not a particularly impressive reason for someone to be attractive. It's not even like it's a big compliment. I think if you take that kind of stuff as a compliment, you're mad. If you think they mean it, or that if you were just a f**king dustman they'd be doing it … Of course they wouldn't. Being famous in itself is not a recommendation.
Martin: I certainly would never ever consciously take over the fun at a wedding. I would be as quiet as a f**king church mouse. I don't particularly like being centre of attention, which is probably one of the reasons I've not got married – because that's worse than a premiere, that's worse than being on stage. I don't really fancy that and Amanda doesn't really like the idea of it all being on you. And I'm very polite because I know people sort of expect something of you that I don't want to deliver. I don't really want to comply and be the funniest man there, because I don't think I am. I happen to be an actor, but that's it.
Martin: My mum was Labour-voting, but wanted us to know we were important. Basically, everyone's equal, but you, my children, are a bit better.
Martin: Some people have that roar in their head, but I'm not sure I ever did. That live-fast-die-young thing. No one wants it really - Jimi Hendrix, Janis Joplin - it's not good. I want to live with Amanda till I'm 70. I was never the kid that went all the way with naughtiness, never got caned or in serious trouble. I always knew when to pull back.
Martin: I don't think it was a surprise that I ended up as an actor, and it was anything but a disappointment. My parents gave me the knowledge that reading isn't a bad thing, and admitting to liking a painting doesn't make you an arse-bandit. And that wouldn't have been a problem either.
Martin: If I could get bands to come and play in my house, I'd like that. I've never been to a festival. I'm a creature of habit, mashed-potato comfort, I like rugs. Our sofa's squishy. Maybe too squishy - it's hard to get up sometimes.
Martin: (on partying with celebrities) God, no. I don't do any of that sh*t. I've got a stag weekend coming up and I've said I'm not doing anything more than a few drinks. I won't have it. I'll go home and watch Antiques Roadshow.
Martin: I'm not a practicing Catholic or I wouldn't be living unwed with a woman, and I don't think all poofs are going to hell, and I don't think everyone who's had an abortion is damned, most of my friends are atheists and I understand atheism, I get it, but I happen to be a theist. I believe in our answerableness to something else.