Royal Air Force Pitreavie Castle or RAF Pitreavie Castle was a station of the Royal Air Force located at Pitreavie Castle in Dunfermline and near Rosyth, Fife, Scotland.

Built in the early 17th century, the castle was sold to the Air Ministry in 1938. An underground bunker was constructed and the station was used to coordinate the operations of RAF Coastal Command and the Royal Navy during the Second World War.

The station was subsequently used as a UK and NATO maritime headquarters before closing in 1996. It is now in residential use.

Pitreavie Castle is thought to have been built by Sir Henry Wardlaw, the 1st Baronet of Pitreavie, who bought the Pitreavie estate in 1608, with the castle believed to have existed by 1614. It was sold to Archibald Primrose, 1st Earl of Rosebery, in 1703, and then to Sir Robert Blackwood, Lord Dean of Guild, and later Lord Provost, of Edinburgh, in 1711. It remained in the Blackwood family for 170 years, but was unoccupied for almost a century. The castle was bought by Henry Beveridge, a wealthy mill owner, in 1884. It was extensively extended and altered in 1885.

Before the outbreak of the Second World War, the Works Department of the Air Ministry was looking for a site to accommodate the headquarters of newly reformed No. 18 (Reconnaissance) Group, part of RAF Coastal Command. In 1938, Pitreavie Castle was found and purchased for £12,306. The building, which was in a dilapidated state, was considered suitable due to the room available for expansion in its large grounds and its close proximity to the Royal Navy base at Rosyth. In 1939, the Admiralty made it known to the RAF that it was interested in co-locating at Pitreavie and creating a joint RAF/Royal Navy Area Combined Headquarters (ACHQ), to which the RAF were agreeable.

In order to protect the important headquarters from potential aerial attack should war break out, work began on an subterranean bunker within the grounds, located to the south-west of the main building. It comprised a two-storey bunker, square in shape, buried 20 feet (6.1 m) underground. It featured two entrances, one for the RAF, leading to an external entrance beside the main building and one leading to the newly built above ground Royal Navy block to the west. It was completed in 1941.

The site became home to the No. 18 Group headquarters, which had responsibility for maritime air operations north of Flamborough Head in Yorkshire, including the areas north and west of Scotland. The Navy's Commander-in-Chief, Rosyth was responsible for naval operations north of Flamborough Head to Wick in Caithness. The site featured a joint Officers' Mess and a steading to the east of the main building was used as a Sergeants' Mess. Towards the end of Second World War, three wooden huts were located to the east of the main building and used to accommodate officers, non-commissioned Officers and other ranks and ratings. The huts were believed to have dated from the First World War and had been relocated from RAF Donibristle, approximately 2.7 km (1.68 mi) away at Dalgety Bay.

During the war, No. 18 Group had responsibility for more than twenty squadrons and controlled aircraft predominately involved in anti-shipping and anti-submarine warfare in the seas around Scotland. The Prime Minister Winston Churchill, visited Pitreavie Castle twice during the war.