John I of Dreux (1215–1249), Count of Dreux and Braine, was the son of Robert III of Dreux and Annora (Aenor) of Saint-Valéry.
Knighted by King Louis IX of France, he accompanied the king on several campaigns, firstly in Poitou in 1242, where he fought at the Battle of Taillebourg. In 1249 he joined the king on the Seventh Crusade to Egypt, but died at Nicosia in the Kingdom of Cyprus before arriving.
In 1240 he married Marie (1220–1274), daughter of Archambaud VIII of Bourbon. They had three children:
- Robert IV (1241–1282), succeeded his father.
- Yolande, became the second wife of John I, Count of Dammartin.
- Rerum Britannicarum medii aevi scriptores, Vol.44, Part 3, Ed. Sir Frederic Madden, (Longmans, Green, and Co, 1869), 564.
- Jochen Schenk, Templar Families: Landowning Families and the Order of the Temple in France, c. 1120-1307, (Cambridge University Press, 2012), 201.
- Michelle Bubenicek, Quand les femmes gouvernent: droit et politique au XIVe siècle:Yolande de Flandre, Droit et politique au XIV siecle, (Ecole des Chartes, 2002), 54.