A tape cartridge includes a platen roller, a winding up core, and a cartridge casing that accommodates a printing tape, an ink ribbon, the platen roller, and the winding up core. The cartridge casing includes an insertion hole in which a head cover on a cartridge installation portion of a tape printing apparatus is inserted when the tape cartridge is installed on the cartridge installation portion. The insertion hole includes a first concave portion and a second concave portion that face a first convex portion and a second convex portion, respectively, on the head cover when the tape cartridge is installed on the cartridge installation portion, and the first concave portion and the second concave portion are formed on an inner wall of the insertion hole.