[7][2] After a conversation with actor Omar Sharif while his father was on a business trip, El-Masry met a screenwriter at a screening of Hassan and Marcus and made his debut in the Egyptian comedy films Ramadan Mabrouk Abu El Alamein Hamouda as Ramzy and El-Talatah Yishtaghaloonha as Nabil.

[2] After graduating from LAMDA, El-Masry first appeared on British television in a 2013 episode of the medical soap opera Casualty as Naveed.

That same year, El-Masry made his professional stage debut in the Royal Court Theatre production of Goats[10][11] and appeared in the Danish series Herrens Veje.

In 2018, El-Masry played Dante in the BBC One drama Age Before Beauty and had a recurring role as Ibrahim in Tom Clancy's Jack Ryan on Amazon Prime.

The following year, he played Kazem in the Egyptian series El-Brinseesa Beesa and Commander Trach in Star Wars: The Rise of Skywalker.

[14] He also has a recurring role in the BBC World War II drama SAS: Rogue Heroes and Jessica Hausner's Club Zero.