A tape cartridge, to be installed in a tape printing apparatus having a cartridge installation portion, includes a tape-shaped member having a plurality of label portions provided along a length direction of the tape-shaped member and a plurality of detection target portions provided along the length direction of the tape-shaped member so as to correspond to the plurality of label portions on one side thereof in a tape width direction projecting in the tape width direction. The tape cartridge further includes a cartridge case in which the tape-shaped member is accommodated so as to be capable of being paid out. The cartridge case has a slit-shaped delivery port. A detection target passage of the tape delivery port, through which the respective detection target portions pass, has a chamfering portion at a corner on an inner surface side of the cartridge case of an edge thereof.