Zyzomys is a genus of rodents with unusually thick, long tails. Five species of the genus are known in Australia, where they are called rock rats or thick-tailed rats. The genus was classified by Michael Rogers Oldfield Thomas in 1909.
There are five known species of rock-rat. The central rock rat (Zyzomys pedunculatus) was once believed to be extinct until rediscovered in 1996.