Ogier the Dane (Holger Danske) is a legendary character who first appears in an Old French chanson de geste, in the cycle of poems Geste de Doon de Mayence.

The 12th-century Danish chronicler Saxo Grammaticus was not familiar with the character, and Ogier has not been connected to any historic event in Denmark. A chronicle from St Martin's monastery in Cologne claims that the monastery had been pillaged by the Saxons in 778, but that it was rebuilt by "Olgerus, dux Daniæ" ("Olger, War-Leader of the Danes"), with the help of Charlemagne.