Alexander McDonell (1786 – November 29, 1861) was an immigration agent and political figure in Upper Canada.
Born in Scotland in 1786, McDonell served with the Glengarry Light Infantry Fencibles during the War of 1812. He was hired by Peter Robinson to help in the development of the settlement at Peterborough. In 1827, he became Crown Lands agent in the Newcastle District.
In 1834, McDonell was elected to the Legislative Assembly of Upper Canada for Northumberland and was reelected in 1836. In 1837, he became colonel in the Northumberland militia and was named justice of the peace for the Newcastle District. He also served as a commissioner responsible for improving navigation along the Trent River. McDonell was not reelected to the legislative assembly in 1841. After that, he became involved in the timber trade, acquiring rights to cut timber along the Bonnechere and Petawawa Rivers.
He died in Peterborough in 1861, but according to his entry in the Dictionary of Canadian Biography Online, his body was refused a Roman Catholic burial "because of his not living to their requirements".