Duff & Phelps, a Kroll business, is a multinational financial consultancy firm based in New York City. Since Duff & Phelps was founded in 1932, the firm has added more than 30 complementary companies to its portfolio, including the 2018 acquisition of Kroll. The original Duff & Phelps was founded in 1932 by William Duff and George Phelps.