Michael H. Steinhardt (born December 7, 1940) is an American billionaire hedge fund manager, investor, and prominent Jewish philanthropist, recognized as a pioneering figure in the hedge fund industry. He graduated from the Wharton School of the University of Pennsylvania with a Bachelor of Science in Economics in 1960 and began his career as a researcher and analyst at firms including Calvin Bullock and Loeb, Rhoades & Co. In 1967, he co-founded the hedge fund Steinhardt, Fine, Berkowitz & Co. (later known as Steinhardt Partners), which achieved remarkable returns, averaging 24% annually until its closure in 1995 amid a federal investigation into insider trading allegations, which he settled without admitting guilt. After a brief retirement focused on philanthropy, Steinhardt returned to finance in 2004 as chairman of WisdomTree Investments, an exchange-traded fund provider, where he has influenced innovative investment strategies. Recognized as 'Wall Street's greatest trader' on the cover of Forbes in January 2014, his net worth was estimated at $1.1 billion as of October 2018, with Celebrity Net Worth citing $1.2 billion.

He is a major philanthropist and supporter of numerous Jewish and pro-Israel causes, focusing on Jewish education and Israel engagement. He is a co-founder of Taglit-Birthright Israel and a co-founder of the Avi Chai Foundation focused on Jewish education and identity. His philanthropic efforts include supporting organizations like Aish HaTorah and Friends of the Israel Defense Forces, having donated hundreds of millions through his family foundation, the Steinhardt Foundation for Jewish Life. He was also a former antiquities collector. His personal life includes a family background tied to organized crime; his father, Sol Frank 'Red' Steinhardt, was a convicted fence for the Genovese Crime Family, associated with figures like Charles 'Lucky' Luciano. Steinhardt was married to Dorrit Steinhardt and has three daughters. He has faced controversies, including a 1995 SEC probe resulting in a $7 million fine and a ban from the industry for four years, as well as repatriating over 180 looted antiquities worth $70 million to Italy, Greece, and Lebanon in 2022 following investigations into illegal trafficking. He also faced sexual harassment allegations in 2019, which led to his forced resignation from the board of Birthright Israel in 2021. His career and philanthropy reflect a blend of financial acumen and commitment to Jewish heritage, though his family's criminal ties, past collecting activities, and the opaque nature of some philanthropic funding have drawn scrutiny and sparked discussions about influence networks. He remains active in investment and charitable endeavors.