The 50th, or Shirley's Regiment of Foot was a British army infantry regiment raised in 1754 in North America during the French and Indian War.
Two regiments were raised in New England with funds supplied by the British Crown, entering the army list as the 50th (Shirley's) and 51st (Pepperrell's) Regiments of Foot. Both regiments took part in the disastrous British campaign of 1755/56. Overwintering near Lake Ontario, the force occupied three forts, Oswego , Ontario and George, collectively known as Fort Pepperrell. Surrounded and besieged by a French force under Montcalm, both regiments surrendered after the local commander was killed. A fair number of the prisoners were massacred by the Indian allies of the French before they reached Montreal.
Both regiments were subsequently removed from the army list and higher numbered regiments were renumbered (i.e. the 52nd Regiment became known as the 50th, the 57th Regiment became the 55th, etc).