Peter Griesar (born 1969) is a keyboardist who played in the Dave Matthews Band in their early days. He grew up in New York and moved to Charlottesville, Virginia to attend college at the University of Virginia. While living in Charlottesville he met Dave Matthews and joined Matthews's band, but Griesar left the band in 1993 because he did not want to spend his life touring around the country.

Griesar went on to play in a band called The Ninth, which also featured Dave Matthews Band bassist Stefan Lessard and eventual Hackensaw Boys founder David Sickmen.

Griesar released several albums as Supertanker and now lives in California, working for an international aid organization. Griesar has also released solo albums, including Superfastgo, Disposable Love Songs, and Candy Shop.