Following a four-year stage career, his first major international onscreen success was in the 2016 BBC miniseries War & Peace, which led to starring roles in feature films.

[21][22] In 2010–11 Lowden was the lead character, Cammy, in the National Theatre of Scotland's revival production of the Olivier Award-winning play Black Watch.

The play is an incisive and topical look at the harsh reality of war, and depicts soldiers of the legendary historic Scottish Black Watch regiment serving in Iraq.

[15] The Black Watch production toured to London (Barbican), Glasgow, Aberdeen, and Belfast, and in the U.S. to New York City, Washington, Chicago, Austin, and Chapel Hill.

[4][23] UK reviewers deemed Lowden "a clearly hugely promising young actor"[24] "who carries off this amazing start to his career with assurance and maturity".

[28] From 9 May 2012 to 5 January 2013 Lowden starred as Scottish runner and missionary Eric Liddell in Chariots of Fire, the stage adaptation of the film of the same name.

He also had a sizable role as a young British soldier in the 2014 film '71, which takes place in Belfast in 1971 during the Northern Ireland conflict.

[36][37][38] The production ran from September 2013 to March 2014, opening at the Almeida Theatre and then transferring in December to the West End at Trafalgar Studios.

The production starred Kristin Scott Thomas as his sister Electra, and Diana Quick played their mother Clytemnestra.

[7][51] In film he played the title role in Tommy's Honour (2016), about legendary Scottish golfing champion Old Tom Morris, played by Peter Mullan, and his complex and bittersweet relationship with his son Tom "Tommy" Morris, Jr.; Lowden was nominated for Best Film Actor at the 2016 BAFTA Scotland Awards for his performance.

[57] He played a Royal Air Force fighter pilot, one of the leading roles, in Christopher Nolan's World War II film Dunkirk, released in July 2017.

... An Olivier Award-winning stage actor now settling into a quietly potent, empathetic screen presence, Lowden impressively holds it together through all these key changes, even when his character emphatically does not.

[68][69][70] On television, in December 2018 he co-starred with Tamara Lawrance and Hayley Atwell, in a three-part BBC adaptation of Andrea Levy's novel The Long Song, about a slave on a sugar plantation in 19th-century Jamaica; the piece was filmed on location in the Dominican Republic.

[73] In February 2019 Lowden teamed up with Beta Cinema to form his own production company, Reiver Pictures, based in Edinburgh.

[74] This led to the production of a psychological thriller, Kindred, in which Lowden also starred alongside Tamara Lawrance and Fiona Shaw.