He is best known for his roles as Pete Dunham in Green Street Hooligans (2005) and as Jax Teller in the FX series Sons of Anarchy (2008–2014). For the latter, he was twice nominated for the Critics' Choice Television Award for Best Actor.

Hunnam also portrayed the title role in Nicholas Nickleby (2002), Raleigh Becket in Pacific Rim (2013), Alan McMichael in Crimson Peak (2015), Percy Fawcett in The Lost City of Z (2016), the title role in King Arthur: Legend of the Sword (2017), William "Ironhead" Miller in Triple Frontier, Raymond Smith in The Gentlemen (both in 2019), and Detective Charlie Waldo in Last Looks (2022).

His other notable television roles include Nathan Maloney in the Channel 4 drama Queer as Folk (1999–2000), Lloyd Haythe on the Fox series Undeclared (2001–2002) and Dale Conti/Lindsay "Linbaba" Ford in the Apple TV+ series Shantaram (2022).