William, Margrave of Hachberg-Sausenberg (died 1482)

Margrave William of Hachberg-Sausenberg was the son of Margrave Rudolf III of Hachberg-Sausenberg and Anne of Freiburg-Neuchâtel. He ruled from 1428 to 1441, and abdicated on 21 June 1441 in favor of his infant sons, Rudolf IV and Hugo. As they were still infants, his cousin Count John of Freiburg-Neuchâtel took over the government as regent.