The Vestry is what other faith traditions commonly term the parish council. The responsibilities of the Vestry include helping define and articulate the mission of the congregation; supporting the church's mission; ensuring effective organization and planning; and managing resources and finances. The Vestry is the legal representative of the parish with regard to all matters pertaining to its corporate property. Vestry members are usually elected at the annual parish meeting to a three-year term. The Priest-in-Charge is the presiding officer of the Vestry.
Among the Vestry are a Senior Warden, Junior Warden, Treasurer and Clerk. At St. Thomas's, the Senior Warden is more involved with Parish leadership, while the Junior Warden is more involved with Day School leadership. In addition, the various ministries of the church are divided among five areas: Fellowship & Witness, Justice & Service, Sacrament & Song, Spiritual Development & Education, and Thanksgiving & Stewardship. Each member of the Vestry provides leadership in one of those areas.
The members of the Vestry and Rector are also the constituent members of the St. Thomas's Day School Corporation, and the Rector serves as its President. In these roles, they fill certain oversight functions for the St. Thomas's Day School Board of Trustees.