HMT Cambridgeshire (FY142) was a British Second World War anti-submarine trawler of the British Royal Navy, named after Cambridgeshire, an English county.
The 443 ton trawler was laid down on 2 July 1935 at Smiths Dock Company of South Bank-on-Tees and completed by the end of the year. It was requisitioned by the Royal Navy in August 1939 shortly before the outbreak of the war and converted to an anti-submarine vessel, armed with a single 4 inch gun, machine guns and depth charges.
On 17 June 1940, the vessel took part in the rescue of passengers and crew from the bombing of RMS Lancastria in the estuary of the River Loire during Operation Ariel. Using the ship's boat, many survivors were picked-up from the water while being bombed and machine gunned by German aircraft. The Cambridgeshire's Lewis gunners claimed to have shot down one of them. An estimated 800 were rescued by the trawler; one of them was Lord Inverclyde. Three members of the Cambridgeshire's crew were decorated for their conduct.
Later that night, Cambridgeshire was ordered to evacuate the commander of the British Expeditionary Force, Lieutenant-General Alan Brooke and his staff to England, because the destroyer allocated was no longer available. There were no rafts or life jackets onboard following the rescue work and the decks were covered in bunker oil and discarded clothing. General Brooke had to clean the oil from his cabin. She left St Nazaire at 3am on 18 June and arrived in Plymouth late on the afternoon of the following day, having acted as an escort to a convoy of evacuation ships en route.
In June 1944, Cambridgeshire took part in Operation Neptune, the naval element of the Normandy Landings. She was sold in 1945, returning to commercial fishing, and was renamed Kingston Sapphire in 1947. The trawler was scrapped at Bruges, Belgium in October 1954.