Robert Winchelsey (or Winchelsea; c. 1245 – 11 May 1313) was an English Catholic theologian and Archbishop of Canterbury. He studied at the universities of Paris and Oxford, and later taught at both. Influenced by Thomas Aquinas, he was a scholastic theologian.

Winchelsey held various benefices in England and was the Chancellor of Oxford University before being elected to Canterbury in early 1293. Although he initially had the support of Edward I, Winchelsey later became a forceful opponent of the king. The archbishop was encouraged by the papacy to resist Edward's attempts to tax the clergy. Winchelsey was also an opponent of the king's treasurer Walter Langton as well as other clergy. On one occasion he rebuked an abbot so sternly that the abbot suffered a fatal heart attack.

Following the election of a former royal clerk as Pope Clement V in 1305, the king was able to secure the archbishop's exile that same year. Upon the succession of Edward's son, Edward II, Winchelsey was allowed to return to England after the new king petitioned the pope to allow his return. Winchelsey soon joined the king's enemies, however, and was the only bishop to object to the return of the king's favourite, Piers Gaveston. Winchelsey died in 1313. Although miracles were alleged to have happened at his tomb, an attempt to have him declared a saint was unsuccessful.