Lawtey began his career with guest appearances in episodes of the CBBC series Wizards vs Aliens and the BBC One medical soap opera Casualty. In 2016, he made his feature film debut in the crime thriller City of Tiny Lights as Charlie Benson. He played Andrew in the second series of the ITV noir detective series Marcella in 2018.

In 2020, Lawtey began starring as Robert Spearing in the BBC Two and HBO series Industry. He also appeared in an episode of the Netflix fantasy series The Letter for the King. This was followed by a small role as Bobby Andrews in Terence Davies' Benediction in 2021.

Lawtey played Cadet Artemis Marquis in the 2022 mystery film The Pale Blue Eye, which had a wide release on Netflix. He has upcoming roles in the ITV romantic-comedy drama You & Me, Todd Phillips' Joker: Folie à Deux, and the biographical film Anna.

Filmography: