Sir Thomas Grey (d. before March 1344) of Heaton Castle in the parish of Cornhill-on-Tweed, Northumberland, was a soldier who served throughout the Wars of Scottish Independence. His experiences were recorded by his son Thomas Grey in his chronicles, and provide a rare picture of the day to day realities of the Wars. His career, blemished by his suicidal charge at the Battle of Bannockburn, a contributing factor to the devastating English defeat, is perhaps best known for his role in the tale of Sir the chivalric knight of Norham Castle.