A tape cartridge is detachably installed on a cartridge installation portion of a tape printing apparatus. A first shaft and a second shaft are disposed on the cartridge installation portion. The tape cartridge includes a printing tape that is wound on a tape core, a platen roller in which a first shaft is inserted when the tape cartridge is installed in the cartridge installation portion, and a guided portion which is guided by the second shaft when the tape cartridge is installed in the cartridge installation portion. When seen from an attaching direction of the tape cartridge, the guided portion is disposed at an opposite side of the tape core with respect to the platen roller and the guided portion is recessed on an outer peripheral surface of a cartridge casing that forms an outer shell of the tape cartridge.