After the Second Partition of Poland, Olszowa became part of the Kingdom of Prussia and fell under the district of Kempen im Possen.

[4] During the 19th and the first half of the 20th century Olszowa was divided into three Gutsbezirke (Polish: obszary dworskie, English: country manor areas).

After World War I, it became part of the Second Polish Republic due to the success of the Greater Poland Uprising.

Following the invasion of Poland and the outbreak of the Second World War in September 1939, Olszowa was occupied by the Wehrmacht and annexed by Nazi Germany.

In 1623, the suffragan bishop of Wrocław, Marcin Kolsdorf, consecrated a new church, which, on July 11, 1659, was endowed by Jan Szyszkowski.

Before the Second World War, the parish priest built the grotto of the Blessed Virgin Mary of Lourdes and organized the construction of the Catholic House (Polish: Dom Katolicki) in 1937.

On the high altar there is a Renaissance triptych painted in 1595, depicting the crucifixion scene with figures of the kneeling founders at the foot of the cross.

The south side-altar created in the Rococo style is from the second half of the 18th century and portrays Mary, the Mother of Sorrows.