Cillian O'Sullivan

The Lost Princess

Alec Touati · 2025

Daredevil: Born Again

Devlin · 2025

The Boy That Never Was

Dave Garrick · 2024

Then You Run

Orin · 2023

Star Trek: Strange New Worlds

Dr. Roger Korby · 2022

In From the Cold

Chauncey · 2022

FBI: Most Wanted

Scot Weitzen · 2020

Misty Button

James · 2019

Maze

Bobby · 2017

Bull

Nathan Alexander · 2016

Halo: Nightfall

Christian Ramsey (uncredited) · 2014

Chicago P.D.

Shane Sullivan · 2014

The Blacklist

Skip Sutherland · 2013

Vikings

Eirik · 2013

Uncle Bill's Barrel

Tom Lynch · 2008

Seacht

Michael · 2008