- Originally began his career as a noted playwright. His first play, The Beauty Queen of Leenane, was successful enough to be transferred to Broadway in April 1998, gaining a Tony award nomination for Best Play during it's run.
- Courted controversy for his comments about disrespecting Theatre in comparison to film, in a 1998 article in BOMB Magazine.
- The first film he wrote and directed, Six Shooter, won him an Academy Award for best live action short film.
- Won the People's Choice Award at the Toronto International Film Festival for Three Billboards Outside Ebbing, Missouri in 2017.