Marta Sosińska-Janczewska (born in Warsaw, 4 October 1939) is a Polish pianist who was awarded the 7th Frédéric Chopin International Piano Competition (1965)'s 3rd prize. She subsequently contributed to a recording of Chopin's complete works. From 1985 on she held a post as professor at the Music University at Würzburg, Germany, where she lives.