Marcin Oleś (born 4 January 1973) is a jazz and free improvisation bass player, composer and record producer. He is the twin brother of Bartłomiej Oleś.
Oles was born on 4 January 1973 in Sosnowiec, Poland. Since his first recording in 2000 he continuously (with his brother Bartłomiej) 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.
In 2003 Marcin Oles became a founding member of the Trio Oles Jörgensmann Oles with his brother Bartłomiej and German clarinet-player Theo Jörgensmann. The last album of this Trio, titled Directions was voted by internet jazz magazine "Diapazon" from Poland as "The Best Recording Of The Year 2005".
He won the individual prize for bass player and drummer at The International Contest Jazz Juniors 99 in Kraków-Poland (1999). He also won the best double bass player of Jazz Nad Odra in Wrocław-Poland (1999)