The Old Catholic Church affirms seven sacraments: Baptism, Confirmation, the Eucharist, Penance (Reconciliation), Anointing of the Sick, Holy Orders, and Matrimony. These are not merely signs or ordinances but genuine means of grace through which Christ's redemptive work is made present and effective in believers' lives. Each sacrament conveys grace ex opere operato (by virtue of the work done), when administered with proper intention and matter.

Baptism is administered to infants as well as adults. Through baptism, original sin is cleansed, and the person is incorporated into the church and receives the gift of the Holy Spirit. Baptism may be by immersion or infusion (pouring/sprinkling). The Eucharist is the source and center of Christian life: the sacramental sacrifice of Christ making his redemptive work present and available. The Old Catholic Church affirms real objective presence—Christ is truly present in the sacrament—while rejecting transubstantiation (the Aristotelian metaphysical explanation used in Roman Catholicism).

The other sacraments address specific life passages and needs: Confirmation strengthens the gift of the Spirit; Penance provides reconciliation with God and church after baptism; Anointing ministers to the sick; Orders ordain men (and women in most branches) to leadership; Matrimony blesses the covenant of marriage. Each sacrament is a visible sign of invisible grace and a means of encountering the risen Christ.