The following are several lists of notable private equity firms based on criteria laid out in each list.

The following is a ranking of the largest private equity firms published in 2011. The ranking was compiled by Private Equity International, which reveals that the world's 50 largest private equity direct investment programs have raised in excess of US$325 billion since 2006. A previous ranking had been published in 2007.

The list includes very few venture capital firms, which tend to be smaller than their leveraged buyout counterparts; for a list of those see List of venture capital firms.

The following is a list of notable private equity firms and merchant banking and other private equity groups that currently reside within investment banking firms or have previously completed a spinout from an investment banking firm:

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^ Defunct banking institution

The following is a list of notable private equity firms:

A private equity firm is an investment manager that makes investments in the private equity of operating companies through a variety of loosely affiliated investment strategies including leveraged buyout, venture capital, and growth capital. Often described as a financial sponsor, each firm will raise funds that will be invested in accordance with one or more specific investment strategies.

Typically, a private equity firm will raise pools of capital, or private equity funds that supply the equity contributions for these transactions. Private equity firms will receive a periodic management fee as well as a share in the profits earned (carried interest) from each private equity fund managed.

Private equity firms, with their investors, will acquire a controlling or substantial minority position in a company and then look to maximize the value of that investment. Private equity firms generally receive a return on their investments through one of the following avenues:

According to an updated 2008 ranking created by industry magazine Private Equity International (The PEI 50), the largest private equity firms include The Carlyle Group, Kohlberg Kravis Roberts, Goldman Sachs Principal Investment Group, The Blackstone Group, Bain Capital and TPG Capital. These firms are typically direct investors in companies rather than investors in the private equity asset class and for the most part the largest private equity investment firms focused primarily on leveraged buyouts rather than venture capital.

Willard Mitt Romney (born March 12, 1947) is an American businessman and the presumptive nominee of the Republican Party for President of the United States in the 2012 election. He was the 70th Governor of Massachusetts (2003–07).

The son of Lenore and George W. Romney (Governor of Michigan, 1963–69), he was raised in Bloomfield Hills, Michigan. In 1966, after one year at Stanford University, he left the United States to spend thirty months in France as a Mormon missionary. In 1969, he married Ann Davies, and the couple had five children together. In 1971, he earned a Bachelor of Arts degree in English from Brigham Young University and, in 1975, a joint Juris Doctor and Master of Business Administration from Harvard University as a Baker Scholar. He entered the management consulting industry, which in 1977, led to a position at Bain & Company. Later serving as Chief Executive Officer, he helped bring the company out of financial crisis. In 1984, he co-founded the spin-off Bain Capital, a private equity investment firm that became highly profitable and one of the largest such firms in the nation. His net worth is estimated at $190–250 million, wealth that has helped fund his political campaigns. Active in The Church of Jesus Christ of Latter-day Saints, he served as Ward Bishop and later Stake President in his area near Boston. He ran as the Republican candidate in the 1994 U.S. Senate election in Massachusetts, losing to long-time incumbent Ted Kennedy. In 1999, he was hired as President and CEO of the Salt Lake Organizing Committee for the 2002 Winter Olympics and Paralympics; and he helped turn the fiscally troubled games into a success.