The King's Head Inn is notable as being the oldest public house with a coaching yard in the south of England. It is located in the Market Square, Aylesbury, Buckinghamshire.

The current structure of the building is of 15th century design, however the cellars are much older.

King Henry VI stayed at the inn while on a tour of the country with his new wife Margaret of Anjou in the 15th century. To commemorate his visit, a stained glass panel was inserted in the front window of the inn showing the king and queen's individual coats of arms. That window is still there, though it is heavily protected. The pub was also renamed to commemorate the visit of Henry IV, and his portrait hangs above the entrance to the inn. It is not known what the inn's original name was.

Oliver Cromwell was another notable visitor to the inn and he stayed there frequently during the English Civil War. He had a device installed in the building using a system of ducts and mirrors so that he could see everyone in the main saloon of the inn from the privacy of his own apartment. This, and some of the furniture from Cromwell's period is also still in use today.

The inn is linked to other churches and establishments in the town via a system of underground tunnels that were in use during the Civil War as escape routes should the town be taken by Royalist troops.

Today the inn is the property of the National Trust. Visitors to Aylesbury are still able to go to the inn and purchase alcoholic beverages in the same way that they would in a normal pub.