cofounder

A cofounder is one of two or more individuals who originate and establish a company or venture. Cofounders share responsibility for creating the business from its inception and typically hold ownership stakes and governance roles alongside other founders. The term is commonly contrasted with a sole founder, who starts a venture alone.

Cofounders usually contribute complementary skills—such as technology, product design, marketing, or operations—and help set the mission, recruit early talent, and raise initial capital. They may assume distinct operational responsibilities, but most startups rely on collaboration and consensus for major strategic decisions.

Equity, titles, and decision rights are typically negotiated at the outset. Many ventures use vesting schedules to align long-term commitment and protect the company if a founder departs. Founders' agreements and shareholder agreements document ownership, IP assignments, and dispute mechanisms.

Notable cofounders include Larry Page and Sergey Brin of Google; Steve Wozniak and Steve Jobs of Apple; and Dustin Moskovitz and Mark Zuckerberg at Facebook, among others. These relationships illustrate how cofounding can combine technical capability with business acumen to launch scalable companies.

Spelling variations—cofounder and co-founder—are common, and both forms are widely understood. In formal contexts, consistent usage within a document is encouraged.