Otto, Duke of Lolland and Estonia

Otto of Denmark, Otto Christoffersen (c. 1310 – after 1346), was the second son of King Christopher II and Euphemia of Pomerania, created Duke of Lolland and Estonia. When Christopher died in 1332 after his elder brother Eric, Otto claimed the crown, but Count Gerhard III of Holstein defeated and captured him near Viborg in October 1334; he was imprisoned at Segeberg.

Released after his younger brother Valdemar IV took the throne in 1340, Otto renounced his claim, went to Germany and joined the Teutonic Order in 1346, which bought his duchy that year.