Marcin Oles (born 1973 in Sosnowiec, Poland) is a jazz and free improvisation bass player, composer and record producer. He is the twin brother of Bartlomiej Oles. Since his first recording in 2000 he continuously (with his brother Bartlomiej) cooperated and performed with musicians such as Theo Jörgensmann, David Murray, William Parker, Herb Robertson, Ken Vandermark, Hamid Drake, Chris Speed, Erik Friedlander a.o.