Stephen Andrew Feinberg (born March 29, 1960) is an American businessman and government official who has served as the 36th United States deputy secretary of defense since 2025. He is the co-founder and former chief executive officer (CEO) of Cerberus Capital Management. Feinberg was also chair of the President's Intelligence Advisory Board from 2018 to 2021, during the first Trump administration.

Feinberg was born to a Jewish family and raised in The Bronx, New York. When aged eight, his family moved to Spring Valley, New York, a suburb of New York City. His father was a steel salesman. He graduated with a Bachelor of Arts in politics from Princeton University in 1982 after completing a 94-page senior thesis titled "The Politics of Prostitution and Drug Legalization." While a student at Princeton, Feinberg captained the tennis team and joined the Reserve Officers' Training Corps.

After graduating from college, Feinberg worked as a trader at Drexel Burnham in 1982 and later at Gruntal & Co.

In 1992, at the age of 32, Feinberg co-founded Cerberus Capital Management with William L. Richter and $10 million under management; by 2024; its assets under management would grow past $60 billion. In 1999, the firm hired former vice president Dan Quayle as a chairman of Cerberus Global Investment. In 2006, the firm hired former United States Secretary of the Treasury John Snow, who serves as a chairman of Cerberus.

In May 2011, Feinberg stated that he believed residential mortgage-backed securities may present "a real opportunity for continued investment for quite a period of time" and that there were opportunities in buying assets from European banks.

Feinberg has said of the pay received by himself and other private equity executives, "In general, I think that all of us are way overpaid in this business. It is almost embarrassing." He has also noted in comments made in 2011 that smaller private equity fund sizes may be better for investor returns: "If your goal is to maximize your return as opposed to assets under management, I think you can be most effective with a big company infrastructure and a little bit smaller fund size."

Feinberg has been described as "secretive" in The New York Times. In 2007, Feinberg controversially told Cerberus shareholders, "If anyone at Cerberus has his picture in the paper and a picture of his apartment, we will do more than fire that person. We will kill him. The jail sentence will be worth it."

Cerberus owned DynCorp, a major private security contractor, from 2010 to 2020, leading to accusations of a conflict of interest during Feinberg's service on the President's Intelligence Advisory Board, and again after his nomination as Deputy Secretary of Defense.