Douglas began his acting career in 2008 with a role in the short film "The Last Day of Summer." He has since appeared in over 30 films and television shows. His most notable roles include:
- Jonathan Kent in the CW superhero series Superman & Lois
- Dr. Nate Heywood / Steel in the DC Comics television series Legends of Tomorrow
- Boyhood (2014)
- The Equalizer (2014)
- American Animals (2018)
Douglas has also done voice work for video games, including Call of Duty: Black Ops II and Grand Theft Auto V.
