Genuflection or genuflexion is the act of bending a knee to the ground, as distinguished from kneeling which more strictly involves both knees. From early times, it has been a gesture of deep respect for a superior. Today, the gesture is common in the Christian religious practices of the Anglicanism, Lutheranism, the Catholic Church, and Western Rite Orthodoxy. The Latin word genuflectio, from which the English word is derived, originally meant kneeling with both knees rather than the rapid dropping to one knee and immediately rising that became customary in Western Europe in the Middle Ages. It is often referred to as "going down on one knee" or "bowing the knee". In Western culture, one genuflects on the left knee to a human dignitary, whether ecclesiastical or civil, while, in Christian churches and chapels, one genuflects on the right knee when the Sacrament is not exposed but in a tabernacle or veiled.

Kneeling is a basic human position where one or both knees touch the ground. Kneeling is defined as “to position the body so that one or both knees rest on the floor,” according to Merriam-Webster. Kneeling when only composed of one knee, and not both, is called genuflection.