Duke Otto II (or Otho) of Brunswick-Osterode (c. 1396âÂÂ1452) was a son of Duke Frederick I of Brunswick-Osterode and his wife, Adelaide of Anhalt-Zerbst, or possibly Elizabeth, heiress of Homburg. He succeeded his father as duke of Brunswick-Osterode in 1421 and ruled jointly with his first cousin once removed Albert II.
Otto was married to Schonetta (or Schonela) (d. 1436), a daughter of Count John I of Nassau-Weilburg. This marriage was childless.