Daniel Seth Loeb (born December 18, 1961) is an American investor, hedge fund manager, and philanthropist best known as the founder and CEO of Third Point LLC, a New York-based hedge fund specializing in event-driven, value-oriented investing and activist strategies. Raised in Santa Monica, California, by his father Ronald Loeb, a partner at the law firm Irell & Manella and general counsel for Williams-Sonoma who also served as a long-time director of Mattel, and his mother Clare Loeb, a historian and scholar, Loeb attended Palisades Charter High School where he was nicknamed 'Milo Minderbinder' for his interest in the stock market. His great-aunt Ruth Handler co-founded Mattel and created the Barbie doll. After his parents' divorce when he was nine, he lived with his father. Loeb graduated from Columbia University with an A.B. in economics in 1983.

Loeb's career began at Warburg Pincus (1984-1987) in private equity, followed by roles as director of corporate development at Island Records securing debt financing, risk arbitrage analyst at Lafer Equity Investors, senior vice-president in distressed debt at Jefferies (1991-1994), and vice president of high-yield bond sales at Citigroup (1994-1995). In 1995, he founded Third Point with $3.4 million, growing it to billions in assets under management through investments in troubled companies, activist campaigns involving public letters demanding changes, and board seats at companies like Yahoo, Sotheby's, and others. Known for his aggressive activist investment strategies and high-profile campaigns, he has faced criticism for short-term focus and ethical concerns but is praised as one of the most successful activists.