Jason Flemyng was born in London, England. His first feature role was in Stephen Sommers' The Jungle Book (1994), and he appeared in Guy Ritchie's first feature film Lock, Stock and Two Smoking Barrels (1998). Flemyng collaborated again with Stephen Sommers for the action-adventure film Deep Rising (1998), and he starred alongside Johnny Depp in From Hell (2001). In 2003, he played the roles of Dr. Henry Jekyll and Edward Hyde in The League of Extraordinary Gentlemen.
Flemyng's other notable roles include Layer Cake (2004), Transporter 2 (2005), The Curious Case of Benjamin Button (2008) and X-Men: First Class (2011). He appeared in the BBC's TV series The Missing (2014-2016) and starred in the 2021 award-winning drama Boiling Point. He has been married to Elly Fairman since 2008.