Traidenis (died 1282) is the Grand Duke of Lithuania from 1270 (or 1269) until 1282.

He is the second most prominent, after Mindaugas, Grand Duke of Lithuania in the 13th century.

His reign ends a seven-year unrest period after Mindaugas is assassinated in 1263 and firmly establishes the Grand Duchy as a pagan state for another hundred years.

Traidenis expands the Grand Duchy into the territories of Sudovians and Semigalians and strengthens its influence in Black Ruthenia.

Unlike Mindaugas, Traidenis does not concentrate on expansion into east.