Thomas Southwell
Thomas Southwell may refer to:
- Thomas Southwell (priest), Canon of Windsor
- Thomas Southwell (died 1568), English landowner and courtier
- Thomas Southwell (died 1643), English landowner
- Thomas Southwell (Jesuit), pseudonym of Thomas Bacon, English-born Jesuit priest, teacher, and theologian
- Sir Thomas Southwell, 1st Baronet, Anglo-Irish politician
- Thomas Southwell, 1st Baron Southwell, Irish MP for Limerick County 1695–1713 and 1715–1717, Commissioner of the Revenue
- Thomas Southwell, [2nd Baron Southwell], his son, Irish MP for Limerick County 1717–1720
- Thomas Southwell, 1st [Viscount Southwell], his son, Irish MP for Enniscorthy and Limerick County 1761–1766
- Thomas Southwell, 2nd Viscount Southwell, his son, Irish MP for Limerick County 1767–1780
- Thomas Southwell, [3rd Viscount Southwell], his son, Irish peer
- Thomas Southwell, [4th Viscount Southwell], his nephew, Irish Lord Lieutenant of Leitrim
- Thomas Southwell, pioneer of the Australian Capital Territory, see Weetangera, [Australian Capital Territory]
- Thomas Southwell (zoologist), British zoologist