After appearing in an episode of the television series Legends in 2015, he had lead roles in the 2016 teen films High Strung and Handsome Devil.

[3][4] His father, Geoffrey Leo Alexander Galitzine, is a co-founder of a glass-recycling company and a former financier in the city of London.

[9] Growing up, Galitzine visited his relatives in the Peloponnese, Athens, and the islands during the holidays, which helped him get in touch with his Greek heritage.

[17] In 2016, he starred in the American drama High Strung, in which he played a young violinist who performs in a subway station.

[21] Galitzine was cast for his first major TV role in the Netflix horror drama series Chambers.

[26] In 2023, Galitzine portrayed high-school football player Jeff in Emma Seligman's sex comedy film Bottoms.

[27] He also starred as one of the leads in the gay romantic comedy film Red, White & Royal Blue, based on the 2019 novel of the same name; he portrays the fictional Prince Henry of England opposite Taylor Zakhar Perez.

[36] On 6 March 2024, Amazon released a single from the movie's fictitious boy band, entitled "Dance Before We Walk".