About St. Sebastian · Greenbrae, California
St. Sebastian Catholic Church is a welcoming Catholic parish in Greenbrae (also addressed as Kentfield-Greenbrae) in Marin County, California, serving the southern Marin community since 1951. The parish is part of the Archdiocese of San Francisco and is centered on the Eucharist, with daily Mass, Saturday vigil, and three Sunday Masses, plus daily Eucharistic Adoration from 7:00 a.m. until noon. Its mission statement declares the parish is 'called by God to live out the message of Christ in love and service to all people,' and its life is sustained by an active staff, dozens of ministries from the Men's Club and St. Martha's Women's Club to the St. Vincent de Paul Society, a Parish School of Religion (PSR), and a long-tenured music program.
- Established
- 1951
- Patron
- St. Sebastian (the Martyr)
- Rector
- Rev. William H. (Bill) Thornton
- Diocese
- Archdiocese of San Francisco
Why belong here
St. Sebastian is a small but very active parish centered on the Eucharist, with daily morning Mass and adoration running from the end of the 7 a.m. Mass until noon — a rhythm of prayer that quietly shapes parish life. Families can raise their children through the Parish School of Religion (grades 1–8), Confirmation preparation, and a CYO basketball program, while adults have a full RCIA process led by Deacon Dave Previtali, weekly men's and women's fellowship groups, and an unusually rich music program under longtime music director Eric Maddox. A working St. Vincent de Paul conference, homebound ministers, lector and usher teams, and a Finance and Parish Council round out the picture of a parish where parishioners are visibly involved in 'love and service to all people.'
Mass times at St. Sebastian
Weekly Mass schedule
Confession times
- Saturdays 3:00 pm–4:30 pm
- Wednesdays 7:00 pm–8:00 pm (or by appointment)
Adoration times
- Daily from 7:00 am Mass until Noon
Mission, Identity & Values
St. Sebastian's self-description on its home page is simple and pastoral: 'St. Sebastian Catholic Church is above all a welcoming Catholic community called by God to live out the message of Christ in love and service to all people.' The parish frames its mission as 'the salvation of souls,' and lists five core values: encouraging lifelong faith formation, supporting personal and communal prayer and the sacramental life of the Church, being centered on the Eucharist, respecting life from conception to natural death, and promoting stewardship as a way of life.
- Mission: the salvation of souls.
- Value: Encourage lifelong faith formation.
- Value: Support personal and communal prayer and the sacramental life of the Church.
- Value: Centered on the Eucharist.
- Value: Respect Life from conception to natural death.
- Value: Promote stewardship as a way of life.
History of St. Sebastian Parish
Saint Sebastian the Martyr was established as a parish in 1951 to serve the growing population of Greenbrae. Until the church building was completed, parishioners worshipped at Marin Catholic High School. The church, designed by San Francisco architects Ryan and Lee, was completed in the mid-1950s (GCatholic dates it to 1956).
- 1951 — Parish established as Saint Sebastian the Martyr.
- 1955–1956 — Church building completed on Bon Air Road.
- 1958 — 21 stained-glass windows installed by Carl Huneke.
- 1967 — Interior rearranged, altar centered on east wall; windows of St. Philip and St. James relocated to south wall.
- 1997 — Church repainted, Lexan installed over windows for protection, new electronic carillon bells added.
The Church Building & Its Art
The building is best known for two artistic programs. Above the main entrance is a cast-concrete bas-relief, in a deliberately medieval style, depicting the Martyrdom of Saint Sebastian — bound at the post with arrows and attended by four angels. Inside, 21 stained-glass windows were designed and installed in 1958 by Carl Huneke of Century Stained Glass Studio, San Francisco, in the style of fourteenth-century Gothic cathedrals; they depict the Apostles, the Evangelists, and saints of special significance to the donors. An oculus rose window in the choir loft depicts St. Sebastian in the Renaissance tradition, raising one arm in the plague-protector pose.
- Architects: Ryan and Lee (Paul Anthony Ryan and John Michael Lee), San Francisco.
- Exterior: cast-concrete bas-relief of the Martyrdom of Saint Sebastian over the main entrance.
- Interior: 21 stained-glass windows by Carl Huneke, 1958, in 14th-century Gothic style.
- Choir loft: oculus rose window depicting St. Sebastian.
- 1967 reordering: altar centered on east wall; St. Philip and St. James windows moved to south wall.
Sacraments
The parish website groups the seven Catholic sacraments under the standard headings of Initiation, Healing, and Vocation. Preparation is coordinated through the parish office and the relevant ministry leaders.
- Sacraments of Initiation: Baptism, Eucharist, Confirmation.
- Sacraments of Healing: Penance (Reconciliation), Anointing of the Sick.
- Sacraments of Vocation: Holy Orders, Matrimony.
- Reconciliation schedule: Saturdays 3:00–4:30 pm; Wednesdays 7:00–8:00 pm or by appointment.
Faith Formation & Religious Education
St. Sebastian's faith formation runs across the life span. The Parish School of Religion (PSR) instructs children in grades 1–8, with dedicated tracks for First Communion/First Penance and Confirmation. Older teens are served through a High School Youth Ministry, and adults are met both through RCIA and ongoing Adult Faith Formation, all coordinated through Deacon Dave Previtali and PSR coordinator Gretchen Harris.
- Religious Education Classes — Grades 1–8.
- Sacrament Preparation for First Communion and First Penance.
- Confirmation Preparation.
- High School Youth Ministry.
- PSR contact: Mrs. Gretchen Harris, [email protected] or (415) 461-0704.
RCIA — Becoming Catholic
The parish runs the Rite of Christian Initiation for Adults as a communal journey back to the early-church formation model. The RCIA team of sponsors and catechists guides inquirers through the classical stages: Pre-Catechumenate (Inquiry), Rite of Initiation, Catechumenate, Rite of Election, Sacraments of Initiation at the Easter Vigil, and Mystagogy. Contact is Deacon Dave Previtali ([email protected]).
- Pre-Catechumenate — Period of Inquiry.
- Rite of Initiation — acceptance into the worshipping community.
- Catechumenate — formation in Catholic tradition and doctrine.
- Rite of Election — catechumens chosen by the bishop.
- Sacraments of Initiation — received at the Easter Vigil.
- Mystagogy — reflection and celebration after reception.
Music & Liturgy
Music at St. Sebastian's is a defining feature of parish life. Music Director Eric Maddox has served the parish for more than 40 years (recognized by the Archdiocese of San Francisco in 2025). Father Bill Thornton has called him 'a world-class musician,' and parish manager Marianne Kambur describes him as 'such an integral part of the lives of the parishioners of St. Sebastian's.' He accompanies liturgy on piano and organ each Sunday. Liturgical lay ministries (lector, usher, altar server, Extraordinary Ministers of the Eucharist) are coordinated by Deacon Dave Previtali.
- Music Director: Eric Maddox (40+ years of service).
- Instrumentation: piano and organ.
- Recognized by the Archdiocese of San Francisco, September 2025.
- Liturgical Lay Ministries coordinated by Deacon Dave Previtali.
Parish Ministries & Groups
A full menu of ministries, service organizations, and fellowship groups is published on the parish website. Opportunities span men's and women's fellowship, youth athletics, outreach to the homebound, social-justice work through the St. Vincent de Paul Society, and parish governance through Parish and Finance Councils.
- Men's Club — last Monday of the month, 7:00–8:30 pm.
- St. Martha's Women's Club — second Saturday of every other month, 9:30 am.
- CYO Basketball — grades 3 through 8.
- St. Vincent de Paul Society — outreach to those in need.
- Homebound Ministers to the Sick.
- Parish Council and Finance Council.
- Altar Society — Gretchen Harris, [email protected].
- Natural Family Planning resources.
Devotions & Parish Life
Beyond the Sunday and weekday schedule, the parish keeps a steady devotional life. Eucharistic Adoration runs every morning after the 7:00 am Mass until Noon, and Stations of the Cross are prayed on Friday evenings during Lent at 7:00 pm. The parish also hosts community-building events such as the Parish Pancake Breakfast after the 9:00 am Sunday Mass and keeps the wider parish informed through a weekly bulletin and a Flocknote channel.
- Eucharistic Adoration — daily, 7:00 am Mass until Noon.
- Stations of the Cross — Friday evenings during Lent, 7:00 pm.
- Parish Pancake Breakfast — occasional Sundays after the 9:00 am Mass.
- Weekly bulletin and Flocknote email channel for parish news.
Staff & Parish Office
The parish staff is intentionally lean: pastor, deacon, parish manager, music director, and key volunteer coordinators. The parish office can be reached at (415) 461-0704 or [email protected] for general inquiries; emergency or sick calls are taken at the same number.
- Rev. Bill Thornton — Pastor.
- Rev. Mr. David Previtali — Deacon; also runs RCIA and several liturgical ministries.
- Marianne Kambur — Parish Manager.
- Eric Maddox — Music Director.
- Gretchen Harris — Altar Society / Parish School of Religion.
- Parish phone: (415) 461-0704. Email: [email protected].
Diocese & Canonical Status
St. Sebastian Parish belongs to the Metropolitan Archdiocese of San Francisco, which lists the parish in its Catholic Directory under 'St. Sebastian Parish, Kentfield' — the Greenbrae/Kentfield postal address being shared across southern Marin. Rev. William H. Thornton is shown in the directory as active since 2009 at this assignment.
- Diocese: Archdiocese of San Francisco.
- Canonical name in archdiocesan directory: St. Sebastian Parish, Kentfield.
- Directory line: 'Rev. William H. Thornton, Active 2009, St. Sebastian Parish, Kentfield.'
Pastors & rectors through the years
- Rev. William H. (Bill) Thornton2009–present
Listed in the Archdiocese of San Francisco Catholic Directory as 'Active 2009 St. Sebastian Parish, Kentfield'; the parish website and sfarch.org profile him as current pastor.