Provided is a sitting posture correction seat that corrects seated posture by sitting thereupon, actively maintains the relationship between the temporomandibular joint, the spine, and the pelvis at correct positions/angles, and performs body adjustment. The sitting posture correction seat (100), which is used alone or loaded on the sitting surface of a chair, is provided with: an ischial bone/pubic bone seat surface portion (110) at which the vicinity of the hip joint of a user is positioned； a thigh seat surface portion (120) at which the thighs are positioned； and a groin seat portion (130) at which the groin space from the base of the hips to the space between the left and right thighs to the left and right kneecaps is positioned. The area from the ischial bone/pubic bone seat surface portion (110) to the end of the thigh seat surface portion (120) is provided with a smoothly forward slanting shape, and the inclination of the thigh seat surface portion (120) is greater than the inclination of the ischial bone/pubic bone seat surface portion (110). Also, the groin seat portion (130) is molded in a manner so as to smoothly become higher from the base of the hips to the space between the kneecaps. While the user is in a seated state, it is possible to adjust the body so that the relationship between the temporomandibular joint, the spine, and the pelvis is the same as in a "correct seiza posture."
