Landerneau is a commune in the Finistère department of Brittany in north-western France.
It lies at the mouth of the Elorn River which divides the Breton provinces of Cornouaille and Léon, 22 km east of Brest. The name is from Lan Terneo and can mean " enclosure of St Ténénan": allegedly a Welshman who also had llans in the Vale of Clwyd in North Wales and in Somerset, and who moved to Brittany in the 7th century. Lann means a religious sacred place. The town has been founded by Saint Arnoc, some times called Ternoc and confusion can occur with Saint Ténénan. Some sources point Saint Arnoc and Saint Ténénan as the same person.
It was an important centre of the flax and linen industries in the 16th and 17th centuries. Landerneau is also the hometown of Édouard Leclerc, a businessman and entrepreneur who founded the French supermarket chain E.Leclerc in 1948. His first store applies a hard competition with other supermarket chains with local made products and lower prices. Leclerc's new methods of sales are still applied in all supermarkets and hypermarkets and marks an evolution in the market's history.