Olli Ahvenlahti (born August 6, 1949 in Helsinki) is a Finnish pianist, composer and conductor.

Since the 1990 Contest, Ahvenlahti following Ossi Runne has been the Finnish conductor at the Eurovision Song Contest. Conducting seven entries until the 1998 Contest, after 1998 the orchestra was abolished. The exceptions are the 1995 Contest and the 1997 Contest in which Finland did not participate although Ahvenlahti acted as Finnish commentator.