Oskar Fajfer (born 30 April 1994) is a motorcycle speedway rider from Poland.
Fajfer first started racing for his home club of Start Gniezno in 2010. He finished 12th in the 2011 Speedway Under-21 World Championship. After spells with Grudziàdz, Toruà  and Gdaà Âsk he returned to Gniezno for the 2019 season.
He also rides in the Swedish and Danish leagues. In 2024 he rode for Piraterna.