Peter Mullan (/ˈmʌlən/; born 1959) is a Scottish actor and filmmaker. His credits include Riff-Raff (1991), Shallow Grave (1994), Braveheart (1995), Trainspotting (1996), My Name Is Joe (1998), The Claim (2000), Neds (2010), War Horse (2011), The Fixer (2008), Top of the Lake (2013), Mum (2016–2019), Ozark (2017–2018), Westworld (2018–2020), Cursed (2020), The North Water (2021), The Underground Railroad (2021), The Lord of the Rings: The Rings of Power (2022–2024), After the Party (2023), Baghead (2023) and I Swear (2025).

He won a Golden Lion at 59th Venice International Film Festival for his direction of The Magdalene Sisters (2002).

Peter Mullan was born in Peterhead, Aberdeenshire, Scotland, the son of Patricia (a nurse) and Charles Mullan (a lab technician at Glasgow University). The seventh of eight children, Mullan was brought up in a working class Roman Catholic family. They later moved to Mosspark, a district in Glasgow. Mullan's father, an alcoholic, became increasingly tyrannical and abusive; he died from lung cancer when Mullan was 17.

For a brief period, Mullan was a member of a street gang while at secondary school, and worked as a bouncer in a number of south-side pubs. He was homeless for short periods at the ages of 15 and 18.

Mullan went on to the University of Glasgow to study economic history and drama, and where he also began acting on stage.

Mullan continued stage acting after graduation. He had roles in films alongside actors such as Robert Carlyle in Riff-Raff (1991), with Mel Gibson in Braveheart (1995), and with Ewan McGregor in Danny Boyle's Shallow Grave (1994) and Trainspotting (1996).

Mullan's role as a recovering alcoholic in My Name Is Joe (1998) won him the Best Actor Award at the 1998 Cannes Film Festival.

As a director, his film, Orphans (1998), won awards at the Venice Film Festival 1998 and Festival du Film de Paris 1999.