Neil Leiper began his film career in 2011 with the horror film "Inbred", where he played Gris. The following year, he played Sniper in "The Angels' Share" (2012), a comedy-drama directed by Ken Loach, which was praised for its humor and warmth.

In 2018, Neil Leiper appeared in the television series "Still Game", a popular Scottish sitcom, where he played the character Coach in an episode of the eighth season. The following year, in 2019, he played Fido in the film "Beats", a drama exploring the 1990s Scottish rave scene, which was acclaimed for its authentic portrayal of underground culture. In 2023, he reunited with director Ken Loach for "The Old Oak", in which he played the role of Rocco. This social drama, faithful to Loach's politically engaged style, was well-received for its poignant social commentary. In 2024, Neil Leiper starred in "On Falling", a drama directed by Laura Carreira, alongside Joana Santos. The film explores the challenges of modern working life and the precarious conditions in which they operate.