The Battle for Brest was fought in August and September 1944 on the Western Front during World War II. Part of the overall Battle for Brittany and the Allied plan for the invasion of mainland Europe called for the capture of port facilities, in order to ensure the timely delivery of the enormous amount of war materiel required to supply the invading Allied forces. It was estimated that the 37 Allied divisions to be on the continent by September 1944 would need 26,000 tons of supplies each day. The main port the Allied forces hoped to seize and put into their service was Brest, in northwestern France.

Brest is a port city in the Finistère department, Brittany. Located in a sheltered bay not far from the western tip of a peninsula and the western extremity of metropolitan France, Brest is an important harbour and the second largest French military port after Toulon. The city is located on the western edge of continental France. With 139,456 inhabitants (2020), Brest forms Western Brittany's largest metropolitan area, ranking third behind only Nantes and Rennes in the whole of historic Brittany, and the 25th most populous city in France (2019); moreover, Brest provides services to the one million inhabitants of Western Brittany. Although Brest is by far the largest city in Finistère, the préfecture of the department is in the much smaller town of Quimper.