Mark O'Brien
Biography
Mark O'Brien is a Canadian actor and director from St. John's. He is best known for playing Des Courtney in Republic of Doyle from 2010 to 2014 and Tom Rendon in Halt and Catch Fire from 2015 to 2016. His portrayal of Terry Sawchuk in the biographical drama Goalie (2019) brought him the Best Actor award at the 8th Canadian Screen Awards. He wrote and directed The Righteous (2021), and his work on it earned him two nominations at the 10th Canadian Screen Awards in 2022, for Best Supporting Actor and Best Original Screenplay. The film also won Best Screenplay at Montreal's Fantasia International Film Festival and at Manchester's Grimmfest, and took cinematography prizes at Grimmfest and Blood in the Snow Canadian Film Festival.
42years old
Turns 43 on May 7in 178 days
- Born St. John's
- Star sign: TaurusThe sign runs April 20 to May 20
Movie Career
- Films
- 15
- Career span
- 10 years2015 to 2025
First and latest
Share
Mark O'Brien movies on Netflix
Nurembergas Colonel John Amen
Shadow of Godas Mason Harper
Seven Veilsas Paul
Blue Bayouas Ace
The Righteousas Aaron Smith
Hammeras Chris Davis
Ready or Notas Alex
Anonas Cyrus Frear
Bad Times at the El Royaleas Larsen Rogers
How It Endsas Jeremiah
Parallelas Josh
The Darkest Mindsas Rob
The Front Runneras Billy Shore
Arrivalas Captain Marks
End of Days, Inc.as Jason
Best known for
The films on Netflix they are best known for, with the part played in each.
Most often with
Four actors appear in two of them each. Pick a number on the chart or a name in the list to see the films they share.
Films together
Forest Whitaker2 films together, 2016 to 2018
Forest Whitaker's page How It Ends2018IMDb rating 5.1O'Brien as JeremiahWhitaker as Tom
Arrival2016IMDb rating 7.9O'Brien as Captain MarksWhitaker as Colonel Weber
Amanda Seyfried2 films together, 2018 to 2023
Amanda Seyfried's page Seven Veils2023IMDb rating 5.6O'Brien as PaulSeyfried as Jeanine
Anon2018IMDb rating 6.1O'Brien as Cyrus FrearSeyfried as The Girl
Henry Czerny2 films together, 2019 to 2021
Henry Czerny's page The Righteous2021IMDb rating 6.0O'Brien as Aaron SmithCzerny as Frederic Mason
Ready or Not2019IMDb rating 6.9O'Brien as AlexCzerny as Tony
Josh Cruddas2 films together, 2018 to 2025
Josh Cruddas's page Shadow of God2025IMDb rating 3.9O'Brien as Mason HarperCruddas as Lucifer
How It Ends2018IMDb rating 5.1O'Brien as JeremiahCruddas as Chad
Box office
What Mark O'Brien's films earned in cinemas worldwide.
Combined worldwide box office
$376 million
8 of the 15 films have a worldwide figure.
Of the 15 films: 8 worldwide figure; 1 us gross only; 3 never in cinemas; 3 figure not found.
- 8Worldwide figure
- 1US gross only
- 3Never in cinemas
- 3Figure not found
Top grosser

Highest grossing
The eight biggest films earned 100% of the total. The bars are drawn to scale.
- 1$203M54.1% of the total
- 2$58M15.3% of the total
- 3$41M10.9% of the total
- 4$37M9.8% of the total
- 5$32M8.5% of the total
- 6$3.3M0.9% of the total
- 7$1.2M0.3% of the total
- 8$750K0.2% of the total











