He is known for starring as Jonathan Byers in the Netflix science fiction horror series Stranger Things (2016–present) and for his roles in feature films like As You Are (2016), Marrowbone (2017), The New Mutants (2020), No Future (2021), and The Souvenir Part II (2021).

[7][5] The year 2015 proved to be a pivotal time for Heaton; he had guest roles on a string of British television dramas and was cast in three major projects, including Stranger Things.

[16] Heaton's breakthrough role was as Jonathan Byers in the Netflix supernatural drama series Stranger Things.

In August 2018, the BBC announced that Heaton would be playing Joseph Merrick, commonly known as the "Elephant Man", in a new two-part drama.

[1][22][23][24] Since 2016, he has been in a relationship with his Stranger Things co-star Natalia Dyer, who plays his character's girlfriend Nancy Wheeler in the series.

[25] In October 2017, Heaton was detained at LAX Airport in Los Angeles for possession of small amounts of cocaine.

[27] Folk-punk band Skinny Lister wrote the song "Charlie" on their 2016 album The Devil, the Heart, and the Fight about Heaton.