Čačvina Castle is the ruins of medieval fortification near the town of Trilj in modern-day Croatia.

Čačvina fortification guarded the approach from Bosnia during the wars with the Ottomans. It is 705 metres (2,313 ft) above sea level about 8 kilometres (5 mi) from the town of Trilj. Its strategic location enabled its occupants to oversee the traffic of goods through the mountain passage that goes through the Dinaric Alps and leads to Bosnia. The first written record of the fortification dates from 1345.