Operation Epsom, also known as the First Battle of the Odon, was a British offensive in the Second World War between 26 and 30 June 1944, during the Battle of Normandy. The offensive was intended to outflank and seize the German-occupied city of Caen from the west, an important Allied objective, in the early stages of Operation Overlord, the Allied invasion of north-west Europe.

Operation Martlet was part of a series of British attacks to capture the French town of Caen and its environs from German forces during the Battle of Normandy of World War II begun by the Allies. It was a preliminary operation undertaken on 25 June 1944 by XXX Corps of the British Second Army, to capture Rauray and the area around Noyers. The attack was to protect the right flank of VIII Corps as it began Operation Epsom, an offensive into the Odon Valley west of Caen, on 26 June. The 50th (Northumbrian) Infantry Division and the 49th Infantry Division were to capture Juvigny-sur-Seulles, Vendes and Rauray, to prevent German counter-attacks against VIII Corps from the area of the Rauray Spur and then extend the attack towards Noyers and Aunay-sur-Odon. It was the first time in Normandy that the 49th Division operated as a division.