Mary Long is a Canadian actress and voice actress, born on August 16, 1951, in Toronto, Ontario. Her career in entertainment began at a very young age; at eight years old, she starred as the title character in the live-action and puppet series Maggie Muggins for the Canadian Broadcasting Corporation. This early start led to extensive work across television, film, and radio throughout her career.

Long is widely recognized for her voice work in English dubs of various anime series that gained popularity in North America. She is notably the voice of Mimmy, Hello Kitty's shy twin sister with a yellow bow, in the television series Hello Kitty and Friends, which originally aired in 1991. Her involvement in the Hello Kitty franchise also extended to later releases, such as the Hello Kitty's Paradise series.

Another significant role in her voice acting career is her contribution to the first English dub of the highly popular Sailor Moon anime. In this series, she provided the voice for several characters, including Molly Baker (known as Naru Osaka in the original Japanese version), Catzy, and various monsters-of-the-day. Her portrayal of Molly with a distinct Brooklyn accent is a notable and discussed aspect of this early dub. She also voiced characters in the Beyblade franchise, including Daichi Sumeragi in Beyblade: The Movie and Beyblade G-Revolution, as well as Jim in the series. Her other voice credits include Tina "Mainframe" Cassidy in the series C.O.P.S. and a role in Totally Spies!.

Beyond voice acting, Long has maintained an active presence in theatre, performing on stages such as Can Stage, Tarragon Theatre, Young People's Theatre, the Shaw Festival, and the Manitoba Theatre Centre in Winnipeg. In addition to her performance career, she is the owner and operator of the StageCoach Theatre Arts School in Toronto, a school dedicated to training children in acting, dance, and singing with a focus on musical theatre.