Nicholas Merbury (died 1421) was an English administrator, Member of Parliament and first Master of the Ordnance. He was probably the son of Sir Thomas Merbury of Northamptonshire. He was the brother of Sir Laurence Merbury, Lord Treasurer of Ireland, and of John Merbury, MP for Herefordshire. He begin his career in the service of Henry Percy, 1st Earl of Northumberland and was present, in September 1402, at the Battle of Humbleton Hill in Northumberland. After Percy's downfall, he transferred his allegiance to King Henry IV.