Kosti Vehanen (31 August 1887 – 13 March 1957) was a Finnish pianist and composer. As a pianist he performed in more than 3,000 concerts on four continents. While he did perform as a concert soloist with major symphony orchestras and performed in recitals, he is best remembered for his prolific work as an accompanist with some of the most important singers of the first half of the 20th century. As a composer, he produced piano pieces, arrangements of folk songs, solo songs, two ballets, and a violin and cello fantasy. In addition, Vehanen also penned several memoirs, including 1941 book chronicling his decade long experience serving as Marian Anderson's accompanist.