- Johnny Depp James Whitey Bulger
- Joel Edgerton John Connolly
- Benedict Cumberbatch Billy Bulger
- Jesse Plemons Kevin Weeks
- David Harbour John Morris
- Dakota Johnson Lindsey Cyr
- Julianne Nicholson Marianne Connolly
- Kevin Bacon Charles McGuire
- Corey Stoll Fred Wyshak
- Peter Sarsgaard Brian Halloran
- Adam Scott Robert Fitzpatrick
- Juno Temple Deborah Hussey
- Rory Cochrane Steve Flemmi
- W. Earl Brown John Martorano
- Bill Camp John Callahan
- Jeremy Strong Josh Bond