Ewan began his professional career in 2004, when he joined the Royal Shakespeare Company for their production of The Merry Wives of Windsor. Ewan spent five years with the Birmingham Repertory Theatre's youth theatre, appearing in a number of plays and musicals with the Rep. After undertaking a BA at the University of Exeter, he attended the Guildford School of Acting, graduating in 2012, winning the Max Adrian Cup for best overall MA student.
Ewan made his television debut in 2014 in BBC's Doctors as young care worker Ben Potter. He previously understudied and played the role of Michael Brown in the UK tour of Terence Rattigan's Less Than Kind, played three roles in Giles Cole’s story of Rattigan's own turbulent life, The Art of Concealment at Riverside Studios, Hammersmith, played Nicholas Beckett in the UK tour of What The Butler Saw, the roles of Eddie/Bradbury in Brian Clemens' Sherlock Holmes and the Ripper Murders, and took a featured role in the 'Unwrap Gold' advert for Cadburys. He has also appeared in commercials for Holland and Barrett, and Crisis. In 2013/14 Ewan made his pantomime debut alongside Gok Wan, Stephanie Beacham and Gary Wilmot at the Birmingham Hippodrome in a brand new production of Snow White. Reprising this role alongside Billy Pearce and Joe McElderry the following year at the Alhambra Theatre, Bradford, he also covered Joe McElderry as the Man in the Mirror. The following year he played Peter in a brand new production of Peter Pan at the Devonshire Park Theatre, Eastbourne.
Ewan is also a voice over artist, and can currently be heard reading SD Sykes' crime novel series for Hodder and Stoughton Audio books, as well as books for Benjamin Zephaniah, Frank Cottrell Boyce and Joanne Harris. He voiced Christophe, a new character for Doctor Who: Ravenous 2, alongside Nichola Walker and Hattie Morohan. He also voices Lobo Howler in the British Netflix animation series, Super Monsters, and Jack in Monty & Co for CBeebies.