Suggestions by @willmoran

Hugh Laurie

as Horace Slughorn in Harry Potter: A TV Series (2009)

Mia Wasikowska

as Grey Lady in Harry Potter: A TV Series (2009)

Emily Watson

as Rowena Ravenclaw in Harry Potter: A TV Series (2009)

Emily Watson

as Grey Lady in Harry Potter: A TV Series (2009)

Kate Winslet

as Molly Weasley in Harry Potter: A TV Series (2009)

James McAvoy

as Sirius Black in Harry Potter: A TV Series (2009)

Georgie Henley

as Hermione Granger in Harry Potter: A TV Series (2009)

Jack O'Connell

as Charlie Weasley in Harry Potter: A TV Series (2009)

Catherine Tate

as Aunt marge in Harry Potter: A TV Series (2009)

Miranda Hart

as The Fat Lady in Harry Potter: A TV Series (2009)

Billy Connolly

as Nearly Headless Nick in Harry Potter: A TV Series (2009)

George MacKay

as Cedric Diggory in Harry Potter: A TV Series (2009)

Nicole Kidman

as Narcissa Malfoy in Harry Potter: A TV Series (2009)

Warwick Davis

as Filius Flitwick in Harry Potter: A TV Series (2009)

Martin Freeman

as Arthur Weasley in Harry Potter: A TV Series (2009)

Daniel Day-Lewis

as Lord Voldemort in Harry Potter: A TV Series (2009)

Jared Harris

as Professor Albus Dumbledore in Harry Potter: A TV Series (2009)

Sean Bean

as Mad-Eye Moody in Harry Potter: A TV Series (2009)

Cillian Murphy

as Lucius Malfoy in Harry Potter: A TV Series (2009)

Rachel Weisz

as Petunia Dursley in Harry Potter: A TV Series (2009)