Mainframe Studios is a Canadian computer animation company owned by Wow Unlimited Media and based in Vancouver, British Columbia. Founded in 1993 as Mainframe Entertainment Inc. by Christopher Brough, Ian Pearson, Phil Mitchell, Gavin Blair and John Grace, the company established itself as a leading contributor to the introduction of computer-generated imagery (CGI) in animation, film and television.

The company previously operated as a subsidiary of Starz Inc. (at the time a division of IDT Corporation) between 2003 and 2007. Local post production firm, Rainmaker Income Fund, acquired a majority stake in the company, initially rebranding it in the process as Rainmaker Animation and would fold into it in 2008, permanently rebranding it as Rainmaker Entertainment. Rainmaker would revive the "Mainframe Entertainment" name for its then-newly-created division meant for television production. On 25 October 2016, the company announced a triple acquisition and merger of Frederator Networks and Erzin-Hirsh Entertainment to create the holding company, WOW! Unlimited Media, and rebrand a second time to Rainmaker Studios. In 2020, the company would rebrand a third and final time to Mainframe Studios to return to their "Mainframe Entertainment" name roots.

The company is best known for the production of the first fully computer-animated television series, ReBoot, Beast Wars, a reimagined relaunch of Transformers from Hasbro and since 2001, in partnership with American toy company, Mattel, the majority of films which later expanded into other audiovisual media to create a multimedia franchise for its flagship fashion doll property, Barbie.