John Harrison O'Donnell (April 7, 1838 – October 26, 1912)[1] was a physician and political figure in Manitoba.

[3] He was born in Simcoe, Upper Canada, the son of John O'Donnell, a native of Ireland, and was educated at Victoria University and Trinity Medical College.

[2] He practised in St. Catharines, Ontario and Montreal[4] before coming to Manitoba during the Red River Rebellion of 1869.

He was a justice of the peace and made out the arrest warrant for Louis Riel when the Wolseley Expedition arrived in 1870.

[5] O'Donnell served as provincial coroner and helped found the Winnipeg General Hospital.