The Mozilla Corporation is a wholly owned subsidiary of the Mozilla Foundation that coordinates and integrates the development of Internet-related applications such as the Firefox web browser, by a global community of open-source developers, some of whom are employed by the corporation itself. The corporation also distributes and promotes these products. Unlike the non-profit Mozilla Foundation, and the Mozilla open source project, founded by the now defunct Netscape Communications Corporation, the Mozilla Corporation is a for-profit entity. The Mozilla Corporation reinvests all of its profits back into the Mozilla projects. The Mozilla Corporation's stated aim is to work towards the Mozilla Foundation's public benefit to "promote choice and innovation on the Internet."

A MozillaZine article explained:

The Mozilla Foundation will ultimately control the activities of the Mozilla Corporation and will retain its 100 percent ownership of the new subsidiary. Any profits made by the Mozilla Corporation will be invested back into the Mozilla project. There will be no shareholders, no stock options will be issued and no dividends will be paid. The Mozilla Corporation will not be floating on the stock market and it will be impossible for any company to take over or buy a stake in the subsidiary. The Mozilla Foundation will continue to own the Mozilla trademarks and other intellectual property and will license them to the Mozilla Corporation. The Foundation will also continue to govern the source code repository and control who is allowed to check in.

The Mozilla Corporation was established on August 3, 2005, to handle the revenue-related operations of the Mozilla Foundation. As a non-profit, the Mozilla Foundation is limited in terms of the types and amounts of revenue it can have. The Mozilla Corporation, which is the for-profit component of the Mozilla Organization, does not have to comply with such strict rules. Upon its creation, the Mozilla Corporation took over several areas from the Mozilla Foundation, including coordination and integration of the development of Firefox and Thunderbird (by the global free software community) and the management of relationships with businesses.

With the creation of the Mozilla Corporation, the rest of the Mozilla Foundation narrowed its focus to concentrate on the Mozilla project's governance and policy issues. In November 2005, with the release of Mozilla Firefox 1.5, the Mozilla Corporation's website at mozilla.com was unveiled as the new home of the Firefox and Thunderbird products online.

In 2006, the Mozilla Corporation generated $66.8 million in revenue and $19.8 million in expenses, with 85% of that revenue coming from Google for "assigning [Google] as the browser's default search engine, and for click-throughs on ads placed on the ensuing search results pages."

Mozilla Taiwan (Chinese: 美商謀智; pinyin: Měishāng Móuzhì) was a branch of the corporation founded in 19 October 2011 (2011-10-19) that promoted and deployed Mozilla products in Taiwan. It ceased operations on 11 August 2020 due to a "significant restructuring" of its parent company.

Most of the revenue of Mozilla Corporation comes from Google (81% in 2022) in exchange of making it the default search engine in Firefox.