Peter Heise (11 February 1830 – 12 September 1879) was a Danish composer, best known for the opera Drot og Marsk (King and Marshal).
Heise's parents tried to press him into becoming a lawyer, but he scored highly in music at school, so he changed direction.
As a young man he collected several hundred folk songs directly from ordinary people.
He did a setting of Hans Christian Andersen's poem Jylland mellem tvende Have (Jutland between two seas) in 1860.
The opera Drot og Marsk tells the story of the murder of a medieval king, and contains some folk ballads.