John Edward Marr FGS FRS (14 June 1857 – 1 October 1933) was a British geologist.
After studying at Lancaster Royal Grammar School, he matriculated to St John's College, Cambridge, graduating with First Class Honours in 1878.
Following undergraduate work in the Lake District, he travelled to Bohemia to investigate the fossil collection of Joachim Barrande, where his work won him the Sedgwick Prize in 1882.
In 1886, Marr became Lecturer at the University of Cambridge Department of Geology, a position he held for 32 years until he succeeded Thomas McKenny Hughes as Woodwardian Professor of Geology in 1917.