Sir Robert Knolles or Knollys (c. 1325 – August 15, 1407) is an important English knight of the Hundred Years' War, who, operating with the tacit support of the Crown, succeeds in taking the only two major French cities, other than Calais and Poitiers, to fall to Edward III.

His methods, however, earn him infamy as a freebooter and a ravager: the ruined gables of burned buildings come to be known as "Knollys' mitres".