Imrie was born in 1994 on the Isle of Wight and is the son of actors Celia Imrie and Benjamin Whitrow.

Between 2001 and 2012, Imrie was educated at Dulwich College, a boarding and day independent school for boys in the south London suburb of Dulwich, followed by the University of Warwick, where he studied English Literature and Theatre Studies. From 2015 to 2017, he studied at the London Academy of Music and Dramatic Art (LAMDA) in London.

Imrie has appeared in a range of stage, television and radio productions since he was a child. After his screen debut in the BBC One film drama Station Jim at the age of five, he appeared in the ITV drama series Kingdom in 2007, and the BBC One mini-series Restless in 2012. In the same year, he appeared in the BBC Two drama series The Hollow Crown, whilst in the following year, he appeared in the BBC One series Father Brown. Prior to attending LAMDA (2015–2017), he appeared at Shakespeare’s Globe in London, playing Bagot in William Shakespeare’s play Richard II (1595) and Ned Spiggett in Jessica Swale’s play Nell Gwynn (2015). He has also appeared in a range of radio productions, including The Treasure Seekers, Charles Dickens’ Great Expectations and John Mortimer’s A Voyage Round My Father.

In 2014, Imrie joined the cast of the long-running BBC Radio 4 series The Archers, based on a rural farming community in the fictional village of Ambridge, to take the role of Josh Archer previously played by child actor Cian Cheesbrough, the teenage son of David and Ruth and one of the main members of the Archer family. In the same year, he played the part of cabin boy Pip in The White Whale at Leeds Dock, in which he sang Amazing Grace from the top of the set after having fallen into the water.

In 2019, Imrie co-starred in the Joe Cornish–directed The Kid Who Would Be King as the young Merlin, with Patrick Stewart portraying Merlin’s older self. He also starred in the independent feature Pond Life alongside Esme Creed-Miles; the film was produced by Dominic Dromgoole, who is the former artistic director of the Globe.