Petnica (Serbian pronunciation: [pětnitsa]) is a small village near Valjevo, Serbia.

The oldest known written document is Petnica Psalms from 1488, which mentions not only the existence of the village of Petnica, but also the monastery and school there.

The Turks burned the monastery in the 18th century, but the church, last renovated in 1864, is still standing.

When digging foundations for building stations, excavators discovered the remains of the old cemetery in Petnica ("Bobija") that were transferred to today's church.

Today, in the back yard of a large research station in Petnica, there are still two of the three school buildings raised in 1925.