Thomas McDonnell (c. 1831–1899) was a military leader in colonial New Zealand.
Thomas McDonnell or McDonell may also refer to:
Thomas McDonnell Sr. (1788–1864), trader and diplomat in colonial New Zealand Thomas John McDonnell (1894–1961), Roman Catholic bishop in the United States Thomas McDonnell (bishop) (1912–1987), Roman Catholic bishop in Ireland Thomas McDonell (born 1986), actor, musician and artist in the United States
See also Thomas Macdonnell, pseudonym used by James Fitz Edmond Cotter (c.1630–1705), Irish soldier and colonial governor