No. 1 Squadron is a squadron of the Royal Air force.

At the outbreak of the Second World War in September 1939 the squadron was deployed to France as part of the RAF Advanced Air Striking Force. In August 1940 the squadron entered the Battle of Britain and was heavily engaged until the 9th September when they were relieved.

On its return to the south of England in December 1940, the squadron began the first of three periods of intruder operations over occupied France. The second covered the first half of 1942. The third spell of intruder missions lasted from January-June 1944.

The first period of intruder missions came to an end in the spring of 1941, when the squadron began a year of night fighter duties. With no radar, the Hurricane did not make a particularly good night fighter, and interceptions were rare.

The second period of intruder duties ended in July 1942 when the Squadron moved the Northumberland to convert to the Typhoon. After six months of preparation, the squadron was ready to use its new aircraft against German fighter bomber raids. In February 1943 it moved back to the south coast to operate against these fast low level raids.

After nearly a year on this duty, No. 1 Squadron began its third spell of intruder operations. During this period it also converted to the Spitfire Mk IX. The intruder missions ended in June 1944 at the start of the German flying-bomb campaign. No. 1 Squadron was one many squadrons moved to south-east England to deal with this new high speed threat.

Finally, with the end of the flying bomb campaign No. 1 Squadron joined the air war against Germany, carrying out long range bomber escort missions in support of the renewed daylight bombing campaign.