Domhnall Gleeson (/ˈdoʊnəl/; born 12 May 1983) is an Irish actor and screenwriter. He is the son of actor Brendan Gleeson, with whom he has appeared in a number of films and theatre projects. He received a Bachelor of Arts in Media Arts from Dublin Institute of Technology.

During the early stages of his career, Gleeson directed and wrote several short films, garnered a Tony Award nomination in 2006 for his role in the Broadway production The Lieutenant of Inishmore, and had a supporting role in Never Let Me Go. He became known to a wider audience for his portrayal of Bill Weasley in the last two entries of the Harry Potter film series (2010–2011), Tim Lake in About Time (2013), and Russell Allen Phillips in the fact-based war drama Unbroken (2014). Gleeson has won three IFTA Awards for his performances in When Harvey Met Bob (2010), Anna Karenina (2012), and Frank (2014).

In the following years, Gleeson received widespread recognition and praise for his performances in several Academy Award-nominated films: Caleb Smith in Ex Machina (2014), Jim Farrell in Brooklyn (2015), and Captain Andrew Henry in The Revenant (2015). He has also starred as General Armitage Hux in the Star Wars sequel trilogy (2015-2019). In 2020, he had a main role in the HBO black comedy series Run. The same year, he was listed at number 21 on The Irish Times list of Ireland's greatest film actors. In 2023 he received a Golden Globe and Critics Choice nomination for his role in the limited series The Patient.

Early life
Gleeson was born the eldest of four boys in Dublin, Ireland. He was raised in Malahide, County Dublin, the eldest son of Mary (née Weldon) and actor Brendan Gleeson. He has three brothers: Fergus, Brian (also an actor), and Rory. He attended Malahide Community School, where he performed in school productions of Grease and King Lear. Gleeson later graduated with a Bachelor of Arts in Media Arts from the Dublin Institute of Technology.