Convoy PQ 18 was one of the Arctic convoys sent from Britain to aid the Soviet Union in the war against Nazi Germany. The convoy departed Loch Ewe, Scotland on 2 September 1942 and arrived in Arkhangelsk on 21 September 1942.
Following the disastrous losses to Convoy PQ 17, the British were determined to provide the convoy with air cover. The new escort carrier HMS Avenger had arrived from the United States and formed the core of the escorting force. The convoy was postponed because a large part of the Royal Navy was engaged in Operation Pedestal, protecting a convoy to Malta in August.
The convoy consisted of forty merchant ships (11 British, 20 US, six Soviet and three Panamanian) and four Fleet auxiliaries; two replenishment oilers, a rescue ship and a CAM ship. Close escort was provided by a force led by Commander A. B. Russell, in the destroyer Malcolm, with two other destroyers Achates and Amazon, two anti-aircraft ships, four Flower-class corvettes, four A/S trawlers and three minesweepers. The escort was supported by a carrier group (the escort carrier Avenger and her accompanying destroyers), and a "Fighting Destroyer Escort" of 16 Fleet destroyers commanded by Rear Admiral Robert Burnett in the cruiser Scylla. The escort was augmented by local escort forces from Britain to Iceland (Campbell and six other destroyers and five trawlers) and from Murmansk (four Soviet destroyers and three minesweepers).