Presbyterian Christology is Chalcedonian: Jesus Christ is one divine person in two natures, fully divine and fully human, without confusion or separation. The Westminster Confession (Chapter VIII) develops Christology through the lens of Christ's mediatorial office — Christ is the mediator of the covenant of grace, the second Adam who where the first failed. Christ fulfills the three offices of prophet (revealing God's will), priest (offering himself as sacrifice and interceding), and king (ruling his church and overcoming enemies).

The munus triplex (threefold office of Christ) is developed with particular thoroughness in the Westminster Larger Catechism (Q&A 42–56). Christ's perfect active obedience (keeping the law on behalf of the elect) and passive obedience (bearing the penalty of the law) are both necessary and together constitute the righteousness imputed to believers in justification. This imputed active obedience is more strongly emphasized in the Westminster tradition than in some other Reformed formulations.