The sacroiliac joint (or sacro-iliac joint; latin: articulatio sacroiliaca) is a discontinuous bone junction in the pelvis, located between the sacrum and the ilium.
The two articular surfaces of the sacroiliac joint are the following:
The sacroiliac joint is covered by a joint capsule and it is strengthened by three short ligaments: the anterior sacroiliac ligament, the posterior sacroiliac ligament, and the interosseous sacroiliac ligament.
The sacroiliac joint is connected by fibers that permit little motion.