[2] Keoghan began acting in 2011 and gained recognition in 2017 for his roles in Christopher Nolan's Dunkirk and Yorgos Lanthimos's The Killing of a Sacred Deer.

Keoghan then starred in the psychological drama Saltburn (2023), for which he gained nominations for a Golden Globe and BAFTA Award for Best Actor.

He has appeared in television, including in the RTÉ drama Love/Hate (2013), the HBO mini-series Chernobyl (2019), the final season of the Netflix reboot Top Boy (2023), and in the Apple TV+ miniseries Masters of the Air (2024).

[8] After appearing in Between the Canals, Keoghan studied acting at The Factory (now Bow Street Academy), a local Dublin drama school.

[8] Keoghan began his acting career in 2011 when he answered a casting notice in a Sheriff Street shop window for the crime film Between the Canals.

He featured as George Mills in Dunkirk and starred as Martin Lang in The Killing of a Sacred Deer alongside Colin Farrell and Nicole Kidman.

[14][9] He won the Irish Film and Television Award for Best Supporting Actor for his work in The Killing of a Sacred Deer.

He portrayed Spencer Reinhart in the film, based on a real-life theft of rare books from a university library.

In 2024, Keoghan was cast as Ringo Starr in a series of four interconnected but separate biopics about the Beatles from filmmaker Sam Mendes.

[4] In March 2024, British luxury fashion house Burberry named Keoghan as its brand ambassador.

[29][30] Keoghan is a supporter of Manchester United and appeared in the club's promotional campaign for the 2024–25 season kit with his second cousin Frank Stapleton.

[35] In September 2021, Keoghan began dating Alyson Kierans, a dental nurse and orthodontic therapist.