Lodewijk III Berthout van Berlaer

Lodewijk III Berthout van Berlaer (1310–1346) was a Brabantine nobleman, the son of Jan II Berthout van Berlaer and Elisabeth van den Berghe. He succeeded his father as lord of Helmond in 1328 and ruled until his death, having married Johanna van Dinther, who bore him his heir Walraven.

He was probably the founder of Helmond Castle, and raised a loan on the security of the castle to pay for its building. He died in 1346 and was buried at Roosendaal.