MacNeill began her career appearing in British television and film.[1] She made her debut guest-starring in an episode of crime drama The Vice and later that year had a minor role in the comedy film, Blackball. In 2005, MacNeill appeared in series 3, episode 2 of Peep Show, playing the character of Mark and Jez's old friend from university, "Canadian" Merry. She promises Jez and Super Hans the disused pub she owns, and has a manic episode shortly afterwards.[5][6] From 2005 to 2007 she starred in the BBC sketch showMan Stroke Woman. She appears in the 2009 film Frequently Asked Questions About Time Travel as a time traveller called Millie.[5] In 2009 she also appeared in production of Mary Stuart which played at the Traverse Theatre in Edinburgh and Linz in Austria.[7]
In 2021 MacNeill was cast as a police detective Sam Wazowski in the CBC comedy-drama series, Pretty Hard Cases opposite Adrienne C. Moore.[12] The series ended in 2023.
