Ninu's Cave is a cave in Xagħra, Gozo, Malta. Ninu's Cave was discovered by local resident Joseph Rapa in 1888 while digging a well under a private house. Ninu's Cave is not far from another underground feature, Xerri's Grotto.
The cave is formed in upper coralline limestone. It has many natural stalactites and stalagmites, and also a few helictites. Many of these formations are dry, with the same colour as the surrounding rock, but a few are semi-transparent.
It also had soda straws, but these have been broken off.
The cave is entered by a 4m descent down a spiral staircase, which ends in a large chamber of approximately 20m by 8m. Ninu's Cave is illuminated by electric lights, and is open to the public all year round.