He was co-ruler of Mecklenburg-Stargard from 1392 or 1393 to 1408 and the sole ruler of Sternberg, Friedland, Fürstenberg and Lychen from 1408 until his death.
He was the eldest child of John I, Duke of Mecklenburg-Stargard, and his third wife Agnes of Lindow-Ruppin.
John II was probably born before 1370 and reigned jointly with his younger brothers Ulrich I and Albert I (d. 1397).
He supported his cousin Albert III, who tried to enforce his rights as a king of Sweden.
In 1388, John II married Catherine ("Wilheida"), the daughter of Grand Duke Algirdas ("Olgierd") of Lithuania.