F. Warren Hellman (July 25, 1934 – December 18, 2011) was an American private equity investor and co-founder of Hellman & Friedman, a multi-billion dollar private equity firm. Hellman also co-founded Hellman, Ferri Investment Associates, today known as Matrix Partners. He started and funded the Hardly Strictly Bluegrass festival. Hellman died on December 18, 2011 of complications from his treatment for leukemia.