Finistère is a department of France in the extreme west of Brittany. Its prefecture is Quimper and its largest city is Brest. In 2019, it had a po…Finistère is a department of France in the extreme west of Brittany. Its prefecture is Quimper and its largest city is Brest. In 2019, it had a population of 915,090. The present department consists of the historical region of Léon and parts of Cornouaille and Trégor, both parts of pre-revolutionary Brittany.