Leif Segerstam (born 2 March 1944 in Vaasa) is a Finnish conductor and composer.
He studied violin, piano and conducting at the Sibelius Academy in Helsinki and conducting at the Juilliard School in New York with Jean Morel.
Segerstam served as chief conductor of the Helsinki Philharmonic Orchestra from 1995 to 2007, and now holds the title of Chief Conductor Emeritus with the orchestra. He has held positions with numerous other orchestras, including the Danish National Radio Symphony and the Austrian Radio Symphony, and has guest-conducted many orchestras throughout the world including the Chicago Symphony, the Los Angeles Philharmonic, the Toronto Symphony and the Brazilian OSESP - the Symphony Orchestra of the State of São Paulo. He is also the professor of conducting at the Sibelius Academy in Helsinki. His students include Susanna Mälkki, Mikk Murdvee, Sasha Mäkilä and Markku Laakso.