He's probably best known for his role as Des Courtney on the CBC series Republic of Doyle, and now Mark O'Brien is stretching his acting chops in a new gig on an American television series. 

O'Brien has been cast as a character on the AMC drama, Halt and Catch Fire

He said landing the role couldn't come at a better point in his career, particularly since Doyle's finale aired in December. 

"It's an interesting time for an actor," he said during an interview with the St. John's Morning Show

"It's pilot season, a great time to meet casting directors and kind of show who you are, and what kind of actor you are, so that they can be aware of you for future things. But I was interested in doing something that was already shooting," he said.

Republic of Doyle cast in St. John's

For six seasons, Mark O'Brien played the role of Des Courtney on CBC's Republic of Doyle. (CBC)

"I really like the show, I think it's a really cool part. It's already had a season and got really good critical reviews. AMC is huge, it's one of my top networks. I think they take risks ... and they really stand by their shows, like Mad Men, Breaking Bad."

O'Brien has been cast in four episodes of Halt and Catch Fire's second season. Shooting has been taking place in Atlanta, GA.

The series is set in the early 1980s, in the halcyon days of the computer tech revolution. 

O'Brien's character, Tom Rendon, is a savvy IT department head at a law firm, who has a passion for gaming.

"I come in and become a whiz ... a brilliant technical wizard. Everyone is making online games and connecting the world through computers for the first time," he said.

"But at the same time, he's not really your typical technical guy. He's very preppy, [a] very put-together guy, a clean-cut guy, which is what interested me. Not every tech wizard is like a nerdy, geeky kind of guy. I thought it was a really interesting take on that."

O'Brien said while his Doyle character Des was a bona fide, gadget-wielding techie — he is not.

"On Doyle, Des was super into that, and this guy is into that too," he said.  

"I loved games growing up. It's cool, we get to play with lots of stuff. A lot of the props, we've got the old Atari, we have 2,600 tapes lying around. There are references to Nintendo, so it's really cool. My interests don't really line up with my characters – yet again," he said. 

Missing home and ROD withdrawal

O'Brien said since Republic of Doyle concluded, the cast has stayed in touch. In fact, O'Brien said he recently spent some time in Dublin with ROD alum, Seán McGinley, who played Malachy Doyle on the show. 

'I really like the show, I think it's a really cool part. It's already had a season and got really good critical reviews.'   - Actor Mark O'Brien on his role in AMC's Halt and Catch Fire

He called Doyle "an institution."

"In Newfoundland, it's something we were all so comfortable with, to the point we were getting to know fans personally. We really came into people's homes with that show," he said.

"I think this summer is going to be odd, because that's when we would normally shoot again. I don't get to go home for six months straight, which is what I got to do every year. I loved that. You just assume you're going home because you've done it for so long." 

O'Brien said his time on Republic of Doyle was invaluable, and landing the role of Des at the age of 24 was "perfect."

"It couldn't have been better timing. I had done quite a bit of theatre and a decent amount of film and TV, but really not a whole lot," he said.

"I was surrounded by such open people on that show. I learned so much ... I was constantly asking questions. The greatest way to learn is by trying things, and that show let me learn so much. I think Doyle did that for me in spades."

Alumni Horizon Award

O'Brien said he hasn't been back to the province in four or five months, and is eager to get home to see family and friends.

"Any reason to come back! I am hoping to get home for the MUN Alumni Awards. They honoured me with the Alumni Horizon Award, so I'm hoping to come back if I can get time off shooting," he said.

"Being down here, it's just so far away  I miss home a lot."  

O'Brien has been nominated for two Canadian Comedy Awards in the last three years for his work as Des on Republic of Doyle.