Drensko Rebro (pronounced [ˈdɾeːnskɔ ˈɾɛːbɾɔ]) is a settlement in the Municipality of Kozje in eastern Slovenia.

The area is part of the historical Styria region.

[2] Drensko Rebro is the site of two known mass graves from the end of the Second World War.

They both contain the remains of Croatians that were disarmed and murdered in May 1945 along the road to Virštanj and at the crossroads between Drensko Rebro and Lesično.

8a Mass Grave (Slovene: Grobišče pri hiši 8a) is located 700 meters (2,300 ft) north of Pilštanj, between a roadside ditch and a slope.