To provide a bathroom chair which can easily be combined to a washbowl with water drainage taken into consideration, and the washbowl having structure advantageous to the bathroom chair.

The bathroom chair 1 comprises a seat face 10 and legs 20 for supporting the seat face 10. The seat face 10 has a locking hole 30 penetrating the face in the thickness direction, and sides defining the locking hole 30 include a front end seal 31 and a rear end side 32 which linearly extend in right and left directions of the seat face 10. The extending length of either of the front end side 31 or the rear end side 32 in the right and left directions is set shorter than the other, and the sides defining the locking hole 30 further include circular sides 33, 33 which circularly or curvedly extend to both ends of the other side (front end side 31 or rear end side 32) from both ends of the side which is set shorter (front end side 31 or rear end side 32).