A tape cartridge is mounted on a mounting section of a tape printer, which has an identification portion configured to identify a type of cartridge containing a tape-shaped printing medium. The tape cartridge includes a tape roll around which the tape-shaped printing medium is wound, a core shaft portion that is formed into a fitting cylindrical shape and has a rotation shaft of the tape roll, an identification concave portion that is provided in an inner peripheral portion of the core shaft and engages with the identification portion, a depressed portion that engages with a pedestal which is disposed on the mounting section, and a core concave portion that includes the identification concave portion and the depressed portion. The identification concave portion is configured to accommodate the identification portion in a state where the tape cartridge is mounted on the mounting section.