Tilda Swinton — Madame Blanc, Dr. Josef Klemperer, Mother Helena Markos, Suspiria (2018)
Michael J. Fox — Marty McFly and Marlene McFly, Back to the Future Part II (1989)
Jonathan Hyde — Sam Parrish and Van Pelt, Jumanji (1995)
Hugh Jackman — Robert Angier, Lord Caldlow, The Prestige (2006)
Dick Van Dyke — Bert and Mr. Dawes Sr., Mary Poppins (1964)
Ben Mendelsohn — Keller and Talos, Captain Marvel (2019)
Warwick Davis — Griphook and Professor Filius Flitwick, Harry Potter movies (2001-2011)
Eugenio Derbez — Felipe and Felipe’s grandmother, Jack and Jill (2011)
Tom Hardy — Reggie and Ronnie Kray, Legend (2015)
James Remar — Ace Speck and Butch Pooch, Django Unchained (2012)
Dean-Charles Chapman — Martyn Lannister and Tommen Baratheon, Game of Thrones (2011-)
Eddie Murphy as Prince Akeem, Clarence, Randy Watson, and Saul in Coming to America (1988)
Benedict Cumberbatch — Dr. Stephen Strange and Dormammu, Doctor Strange (2016)
Margaret Hamilton — Miss Almira Gulch and The Wicked Witch Of The West, The Wizard Of Oz (1939)
Ryan Reynolds — Deadpool and the voice of Juggernaut, Deadpool 2 (2018)
Arsenio Hall — Semmi, Morris, a girl in a bar, and Reverend Brown in Coming to America (1988)
Johnny Mo (the boss of the crazy 88)
&
Pai Mei (the old Chinese Kung Fu Master with the astonishing eyebrows )
Dustin Hoffman in Tootsie:
Michael Dorsey
&
Dorothy Michaels
______________________
Robin Williams in Mrs. Doubtfire
Daniel Hillard
&
Mrs. Euphegenia Doubtfire
I saved that as 3 (now 4) comments, why is that sorcery adding every thing to my 1st comment?
Technically Dustin Hoffman and Robin Williams were the same character, just in drag.