Lehnin Abbey is a former Cistercian monastery in Lehnin in Brandenburg, Germany. Since 1911 it has accommodated the Luise-Henrietten-Stift, a Protestant women’s community.
The abbey was founded in 1180 with the support of Otto I, Margrave of Brandenburg as a daughter house of Sittichenbach Abbey. In its turn it founded four daughter houses: the abbeys of Paradiz (1236), Mariensee (1258), Chorin (1260) and Himmelpfort (1299).
It was an important contributor to the land development of the Margraviate of Brandenburg. It was dissolved in 1542 during the Reformation.
Since 1911 it has housed the Protestant religious community known as the Luise-Henrietten-Stift.