In the early Piast period, a fortified settlement existed nearby the town. Ośno Lubuskie was mentioned for the first time in 1252, as " civitas forensi Osna ". The privilege of the city was received in 1282 from the bishops of Lubusz and the first mayor of the city was Dzierżko of Chyciny. At the beginning, Ośno was owned by the Bishops of Lubusz, and since 1258 by the Brandenburg margraves. Formally, the bishops gave the city to Brandenburg in 1401. Prior to 1347 Ośno Lubusz received full civic rights and in 1369 it received the right to mint its own coins. Initially it was a fortified trading settlement, but over the time it evolved into a city. During the late Middle Ages Ośno became the center of Torzymska plain, and became the capital from 1447, when the county was established.
The city was several times on fire and it did not avoid war and pestilence. Before the war Drossen was famous for its beer produced in the Drossen brewery, plantation of flowers, asparagus and currants.
In 1945 due to heavy bombing and battles nearby, the city was left 70% destroyed. After the war Drossen was incorporated into Poland and was renamed Ośno Lubuskie. All German residents were expelled to Germany.