Provided is a printing cassette that can reduce damage to a gear that transmits a driving force. The present disclosure discloses a printing cassette that includes: a case including a first case portion, a second case portion, and a third case portion; a first tape, at least a portion of which is accommodated in the third case portion; and a gear, a portion of which is accommodated in the second case portion, the gear being rotatable about a rotation axis parallel to a first direction, wherein: the first case portion has an outlet through which the first tape is discharged; the first case portion, the second case portion, and the third case portion are disposed in an order of the first case portion, the second case portion, and the third case portion in the first direction; the first case portion includes: a protruding portion having a first surface defining a head opening; and a facing portion defining the head opening, the facing portion having a second surface facing the first surface in a second direction orthogonal to the first direction; the second case portion has a third surface, the third surface being disposed at an end of the head opening in the first direction and connecting between the protruding portion and the facing portion; and the gear is partially exposed to the head opening.