The Surveyor-General of the Ordnance was a subordinate of the Master-General of the Ordnance and a member of the Board of Ordnance, a British government body, from its constitution in 1597. Appointments to the post were made by the crown under Letters Patent. His duties were to examine the ordnance received to see that it was of good quality. He also came to be responsible for the mapping of fortifications and eventually of all Great Britain, through the Ordnance Survey, and it is this role that is generally associated with surveyor-generalship.

The Board of Ordnance was a British government body. Established in the Tudor period, it had its headquarters in the Tower of London. Its primary responsibilities were 'to act as custodian of the lands, depots and forts required for the defence of the realm and its overseas possessions, and as the supplier of munitions and equipment to both the Army and the Navy'. The Board also maintained and directed the Artillery and Engineer corps, which it founded in the 18th century. By the 19th century, the Board of Ordnance was second in size only to HM Treasury among government departments. The Board lasted until 1855, at which point it was disbanded.