A tape cartridge is provided that can be smoothly attached/detached to/from a cartridge installation portion. Disclosed is a tape cartridge 100 attachably/detachably installed in a tape printing apparatus 1 having two guide pins 48 and 50 that guide the attachment/detachment of the tape cartridge 100 to/from a cartridge installation portion 5. The tape cartridge 100 comprises: a cartridge casing 130 having a pair of finger-hooking projections 304 on a side surface thereof; a platen roller 120 guided by one of the guide pins 48 when the tape cartridge 100 is attached/detached; and a guided portion 182 guided by the other of the guide pins 48 when the tape cartridge 100 is attached/detached, wherein the guided portion 182 is disposed at a far position of the cartridge casing 130, the far position being the farthest position over an imaginary line L connecting the pair of finger-hooking projections 304 together with respect to the platen roller 120.