In-Vehicle Door Latch Structure and Vehicle

A latch structure includes: a door that is changeable between a closed state in which the door covers a door opening provided on a peripheral wall of a vehicle and an opened state in which the door opens the door opening; a floor panel that constitutes a floor surface of an interior space; a door-side engaging portion mounted on the door; and a floor-side engaging portion mounted on the floor panel and engageable with the door-side engaging portion when the door is in the closed state.