Thomas Tull founded Legendary Entertainment after raising $500 million from private equity firms. It was one of the first companies of its kind to pair major motion picture production with major Wall Street private equity and hedge fund investors, including ABRY Partners, AIG Direct Investments, Bank of America Capital Investors, Columbia Capital, Falcon Investment Advisors, and M/C Venture Partners. Legendary Pictures, Inc. was incorporated in California in 2000 and in 2005 it signed an agreement with Warner Bros. to co-produce and co-finance up to 40 films over seven years. In 2010, Tull, Fidelity Investments, and Fortress Investment Group bought all the shares of the original investors. The buyout also included a $25 million-investment by Orange Sky Golden Harvest Entertainment. Following the transaction, Tull became the largest shareholder, thus enabling him to more easily direct the company's operations. Golden Harvest later sold its stake in the company for $30 million. In 2011, Accel Partners bought $40 million-worth of shares and Accel partner Jim Breyer joined the company's board of directors. That same year the company was reported to have been valued at more than $1 billion. In September 2011, Chief Creative Officer Jon Jashni was appointed to the new position of President. In December 2012, Waddell & Reed bought around 20% of Legendary's shares for $443 million.
In July 2013, Legendary reached an agreement with Universal Pictures in which it will market, co-finance, and distribute Legendary's films for five years starting in 2014, the year that Legendary's similar agreement with Warner Bros. expires. In October 2014, SoftBank bought $250 million shares, a 10% stake, in Legendary. The transaction increased the company's total value to around $3 billion.
In 2014, Legendary acquired the TV producer Asylum Entertainment, which made ESPN's 30 for 30 and miniseries The Kennedys, for $100 million, but Asylum Entertainment will continue operating as a separate company.
On January 11, 2016, Chinese conglomerate Wanda Group announced that it concluded an agreement with shareholders to acquire Legendary Entertainment for $3.5 billion, making it the largest acquisition of an American media company by a Chinese firm.
On January 17, 2017, it was announced that Tull had exited as Legendary Entertainment CEO. He was replaced by the senior vice president of Wanda's cultural industry group, Jack Gao, as interim CEO.
On October 17, 2017, it was reported that Gao stepped down from his positions at Legendary Entertainment and Wanda Group. The resignation comes after an announcement by Wanda's chairman Wang Jianlin earlier that year that Wanda would refocus its investments onto the Chinese domestic market in an attempt to "actively respond to the call of the country". This, in turn, is thought to be a consequence of the Chinese government banning Chinese banks to provide loans to Wanda Group's foreign operations intended to stop the firm's offshore acquisition plans.
On December 5, 2017, it was announced that Joshua Grode had been named as Legendary Entertainment CEO.