Sidney Painter (September 23, 1902 – January 12, 1960) was an American medievalist and historian.

Painter was born in New York City; after the Taft School he attended Yale University (AB 1925; PhD 1930).

[1] He was an influential member of American academia in the 1950s and served on many boards and committees.

His doctoral thesis was later published as "William Marshal: Knight-Errant, Baron, and Regent of England", and was supervised by Professor Sydney K. Mitchell at Yale University.

[5] He was an expert in medieval institutions but also believed in relating history from personal perspectives.