Šentjernej ( or ; in older sources also Šent Jernej, Sankt Bartlmä ) is a small town in southeastern Slovenia. It is the seat of the Municipality of Šentjernej. It lies in the center of the Šentjernej Plain (Šentjernejsko polje), which is part of the larger Krka Flat (Krška ravan). The area is part of the traditional region of Lower Carniola. It is now included in the Southeast Slovenia Statistical Region.
The parish church, from which the town also gets its name, is dedicated to Saint Bartholomew (sveti Jernej) and belongs to the Roman Catholic Diocese of Novo Mesto. It is a Baroque building with remains of two earlier churches, one Romanesque from the 12th century and the other a 15th-century Gothic one, preserved in the floor of the current building. Two 18th-century side altars were brought to the church from the Cistercian monastery at Kostanjevica.