Peter I, Count of Dreux

Peter I of Dreux (1298–1345) was the youngest son of Count John II and Jeanne of Beaujeu, and inherited her lordship of Montpensier. In 1328 he fought for Philip VI against the Flemish rebels at Cassel. The county of Dreux came to him only in 1331, after his elder brothers Robert V and John III had both died without heirs.

In 1341 he married Isabeau of Melun. He died on 3 November 1345; his infant daughter Joan died the next year, and the county passed to his sister Joan II.