Isaac Marshall Harrison (8 June 1880 – 25 February 1909) was an English cricketer. Harrison's batting style is unknown. He was born at Calverton, Nottinghamshire.
Harrison made his first-class debut for Nottinghamshire against Middlesex at Lord's in the 1901 County Championship. He made six further first-class appearances in that season for the county, the last of which came against Lancashire at Old Trafford. In his seven first-class appearances for the county, he scored a total of 143 runs at an average of 14.30, with a high score of 33.
He died at the village of his birth on 25 February 1909, following ill-health which had led him to give up playing cricket.