Kelly Macdonald
It’s surprising to think that Kelly Macdonald, who first appeared in 1996’s Trainspotting, was once a barmaid. After reading an open cast leaflet for the comedy-drama film, she won the part of Diane. She reprised the role in 2017’s T2 Trainspotting, which did reasonably well at the box office.
A quarter of a century later and Kelly is still a highly respected TV and film actress. She appeared on HBO’s Boardwalk Empire from 2010 to 2014. However, we’ll forever know her for her brief stint in the final installments of the Harry Potter movies (Grey Lady, a.k.a. Helena Ravenclaw).