The satisfaction theory of atonement is a theory of the atonement which holds that Jesus Christ redeemed humanity through making satisfaction for humankind's disobedience through his own supererogatory obedience. The theory draws primarily from the works of Anselm of Canterbury, specifically his Cur Deus Homo ('Why Was God a Man?'). Since one of God's characteristics is justice, affronts to that justice must be atoned for. It is thus connected with the legal concept of balancing out an injustice.

Anselm regarded his satisfaction view of the atonement as a distinct improvement over the older ransom theory of atonement, which he saw as inadequate, due to its notion of a debt being owed to the devil. Anselm's theory was a precursor to the theology of later theologians like John Calvin, who taught the idea of Christ suffering the Father's just punishment as a vicarious substitute.

The classic Anselmian formulation of the satisfaction view should be distinguished from penal substitution. Both are forms of satisfaction theory in that they speak of how Christ's death was satisfactory, but penal substitution and Anselmian satisfaction offer different understandings of how Christ's death was satisfactory. Anselm speaks of human sin as defrauding God of the honour he is due. Christ's death, the ultimate act of obedience, brings God great honour. As it was beyond the call of duty for Christ, it is more honour than he was obliged to give. Christ's surplus can therefore repay our deficit. Hence Christ's death is substitutionary; he pays the honour to the Father instead of our paying. Penal substitution differs in that it sees Christ's death not as repaying God for lost honour but rather paying the penalty of death that had always been the moral consequence for sin (e.g., Genesis 2:17; Romans 6:23). The key difference here is that for Anselm, satisfaction is an alternative to punishment, "it is necessary either that the honor taken away be repaid, or else that punishment follow." By Christ satisfying our debt of honor to God, we avoid punishment. In Calvinist penal substitution, it is the punishment which satisfies the demands of justice.^{[citation needed]}

Another distinction must be made between penal substitution (Christ punished instead of us) and substitutionary atonement (Christ suffers for us). Both affirm the substitutionary and vicarious nature of the atonement, but penal substitution offers a specific explanation as to what the suffering is for: punishment.^{[citation needed]}

Augustine teaches substitutionary atonement. However, the specific interpretation differed as to what this suffering for sinners meant. The early Church Fathers, including Athanasius and Augustine, taught that through Christ's suffering in humanity's place, he overcame and liberated us from death and the devil. Thus while the idea of substitutionary atonement is present in nearly all atonement theories,^{[citation needed]} the specific idea of satisfaction and penal substitution are later developments in the Latin church.^{[citation needed]}

Anselm of Canterbury first articulated the satisfaction view in his Cur Deus Homo?, as a modification to the ransom theory that was postulated at the time in the West. The then-current ransom theory of the atonement held that Jesus' death paid a ransom to Satan, allowing God to rescue those under Satan's bondage. For Anselm, this solution was inadequate. Why should the Son of God have to become a human to pay a ransom? Why should God owe anything at all to Satan?

Instead, Anselm suggested that we owe God a debt of honor: "This is the debt which man and angel owe to God, and no one who pays this debt commits sin; but every one who does not pay it sins. This is justice, or uprightness of will, which makes a being just or upright in heart, that is, in will; and this is the sole and complete debt of honor which we owe to God, and which God requires of us." Having failed to render to God this debt, it is not enough to restore the justice originally owed, but the offense to God's honor must be satisfied, too. "Moreover, so long as he does not restore what he has taken away, he remains in fault; and it will not suffice merely to restore what has been taken away, but, considering the contempt offered, he ought to restore more than he took away." This debt creates an imbalance in the moral universe; God cannot simply ignore it according to Anselm. The only way to satisfy the debt was for a being of infinite greatness, acting as a man on behalf of men, to repay the debt of justice owed to God and satisfy the injury to divine honor. In light of this view, the "ransom" that Jesus mentions in the Gospels would be a sacrifice and a debt paid only to God the Father.

Anselm did not speak directly to the later Calvinist concern for the scope of the satisfaction for sins, whether it was paid for all mankind universally or only for limited individuals, but indirectly his language suggests the former. Thomas Aquinas later specifically attributes a universal scope to this atonement theory in keeping with previous Catholic dogma, as do Lutherans at the time of the Reformation.