Tree rat or tree-rat may refer to the following rodents:

• Black rat (Rattus rattus), occurring worldwide;
• Brachytarsomys (several species), from Madagascar;
• Callistomys (the painted tree-rat), from Brazil;
• Carpomys, from the Philippines;
• Chiromyscus (Fea's tree rat), from southeastern Asia;
• Conilurus, from Australia and southern New Guinea;
• Diplomys labilis, the rufous tree rat, from Panama, Colombia, and Ecuador;
• Diplothrix, the Ryukyus Islands tree rat, from the Ryukyu Islands;
• Echimys, from Amazonia;
• Kadarsanomys, Sody's tree rat, from Java;
• Lenothrix, the gray tree rat, from Southeast Asia;
• Lonchothrix, the tuft-tailed spiny tree rat, from Brazil;
• Makalata, from Amazonia;
• Mesembriomys, from Australia;
• Mesomys, from Amazonia;
• Niviventer langbianis, the dark-tailed tree rat, from Southeast Asia;
• Papagomys armandvillei, the Flores giant tree rat, from Flores;
• Pattonomys, from South America;
• Phyllomys, from the Atlantic Forest of eastern South America;
• Pithecheir, from Southeast Asia;
• Santamartamys, the red crested tree rat, from Colombia;
• Thallomys nigricauda, the black-tailed tree rat, from southwestern Africa;
• Toromys, the giant tree rat, from Brazil;
• Xenuromys, the mimic tree-rat, from New Guinea.