Susan Blu, sometimes credited as Sue Blu, is an American voice actress, voice director, and casting director in American and Canadian cinema and television. She most notably voiced Arcee in the original Transformers movie and also in Seasons 3 and 4 of The Transformers, and is also well-known for playing the roles of Stormer and Lindsay Pierce in the 80s animated series, Jem.

Other voice roles include Granny Smurf on Smurfs, Judge J.B. McBride on Bravestar, Jessica Wray, Futura, Time Hopper and Belfry in Filmation's Ghostbusters, Aimee Brightower in Galaxy High, Kim on Fangface, Lofty and Buttons and other minor characters on My Little Pony, the character Transmutate in the episode of the same name of the series Beast Wars, and one of Petrie's brothers and sisters in The Land Before Time XII: The Great Day of the Flyers. She even played Princess PawPaw on Hanna-Barbera's Paw Paws and the Sphinx on Tiny Toon Adventures.

Blu is the voice director for the Ocean Group, a Canadian-based company most notable for providing the voice-actors for Viz Communications and Beast Wars series. She was the voice director for Beast Wars, a prequel (and sequel) of Transformers, and the sequel, Beast Machines. She was the dialog director on the Teenage Mutant Ninja Turtles (1987 TV series) and is also the voice director on the Teenage Mutant Ninja Turtles (2003 TV series). Currently she is now the voice director for Transformers Animated and reprised the role of Arcee.

Blu's on-screen appearances include the role of Mrs. Shepard in Friday the 13th Part VII: The New Blood, and an appearance in the television series Knight Rider.