Zaderc (pronounced [ˈzaːdɛɾts]; also Zadrc,[1][2] German: Saderz[1][3]) is a former settlement in the Municipality of Kočevje in southern Slovenia.

[5] The origin of the name Zaderc is uncertain; the Slovene linguist France Bezlaj tentatively suggested that it may be a fused prepositional phrase, derived from *za-dorьcь.

In 1953 it was inhabited by two Roma families (Brajdič and Hudorovac), who worked at the gravel pit at Čeplje.

[5] The ruins of a chapel dedicated to Saint Francis Xavier are located in Zaderc.

The chapel dated from the mid-18th century and had an octagonal altar section walled on three sides and a stone portico.