Saint Audomare (died c. 670), the seventh-century saint whose name is often shortened as "St. Omer"
Godfrey de Saint-Omer (12th century), one of the 12th century founders of the Knights Templar
Nicholas I of Saint Omer (11??-121?), French knight who participated in the Fourth Crusade and became a lord in the Frankish Duchy of Athens, father of Bela
Bela of Saint Omer (died 1258), Lord of one half of Thebes, father of Nicholas II, Otho and John