Thomas Aldersey (1521/22 – December 1598; also Aldersay or Aldersaye) was an English merchant, haberdasher, member of Parliament and philanthropist. A contemporary description placed him among the "wisest and best merchants in London", and he was particularly known for his efforts to set the Protestant colony of Emden on a secure trade footing. His charitable works included the establishment of a free grammar school at his birthplace of Bunbury in Cheshire.
Aldersey was born in Bunbury, Cheshire. His father, John Aldersey (c. 1494–1554) of Aldersey Hall, was a landowner from Spurstow. His mother, Anne (or Agnes), was the daughter of Thomas Bird of Clutton or Colton. Several members of the Aldersey family were prominent in 16th-century Chester. Thomas Aldersey was the second of several sons of the marriage. He was educated in Bunbury, possibly at the Chantry House.