St. Mary's Parish

"To know Christ and to make Him known..."


St. Mary's Catholic Church
8 Church St
Holliston, MA 01746
Rectory 508∙429∙4427 or 508∙879∙2322
Religious Education
FAX 508∙429∙3324

Parish Clergy

Rev. Mark J. Coiro, Pastor

Rev. Mr. Joel Americo Santos, Transitional Deacon
Deacon John Barry, Permanent Deacon
Deacon Martin Breinlinger, Senior Deacon


Rev. Mark J. Coiro

Pastor, (photo top center group)

Fr. Mark is a 1990 graduate of St. Anselm College in Manchester New Hampshire, where he received his Bachelor’s Degree in Theology and Certification in Classics in 1990. He then attended St. John’s Seminary in Boston, receiving his Master of Divinity with a specialization in Systematic Theology in 1994.

While in seminary he joined the United States Army Reserve as a Chaplain Candidate, being commissioned a Lieutenant in the Staff Specialist Branch. In this capacity he served active duty tours at Fort Leonard Wood, MO; Letterman U.S. Army Hospital in San Francisco; and also with the 364th Armor Battalion in Schweinfurt, Germany.

On May 21, 1994 he was ordained a priest at the Cathedral of the Holy Cross in Boston. Fr. Mark said his First Mass of Thanksgiving at St. Clement’s Parish in Somerville, then served as Parochial Vicar in the Parishes of St. Theresa’s in Billerica, St. Jerome’s in N. Weymouth, and St. Joseph’s in Medway.

In October of 2005, Archbishop Sean O’Malley ended Fr. Mark’s assignment as Parochial Vicar in Medway, and named him as the fourteenth Pastor of the neighboring parish of St. Mary’s, Holliston.  Father Mark is always available to meet with parishioners to hear their ideas, needs, concerns, and dreams for St. Mary’s Parish.  He considers himself truly blessed to be part of one of the most vibrant and spirit filled parishes in our Archdiocese.

In addition to his parish ministry, Fr. Mark is privileged to serve the Church as a Knight of the Equestrian Order of the Holy Sepulchre of Jerusalem.  Let us all pray and work for peace in the Holy Land, and together support our Christian brothers and sisters in the land of Our Saviour’s birth.

Rev. Mr. Joel Americo SantosRev. Mr. Joel Americo Santos
Transitional Deacon, (photo left)

Americo Santos was born in San Salvador, El Salvador, Central America. He grew up in a town in the north region of his country, where his family still lives. Americo attended primary and high schools in El Salvador, then went on to the Diocesan Seminary Juan XXIII to study philosophy for three years as a Seminarian for the Diocese of Chalatenango, El Salvador. He finished the philosophy program and then went to the Seminary of San Jose de la Montana to study theology in San Salvador. He was there for two years but left the program and worked as a religion teacher at a Catholic School in his home town and as a youth minister. At the same time he continued studying Theology at the Jesuit University in San Salvador. He received his Masters in Theology from that University.

Over the years, Americo used to visit Boston frequently. During one visit he met Fathers Joseph Gaudet and Gerald Osterman from Immaculate Conception Parish in Everett. They helped him with his vocational discernment, and eventually encouraged him to apply to St John's Seminary in Brighton to be a priest for the Archdiocese of Boston. Americo was accepted and came to Boston in the fall of 2010. He studied English as a second Language in Boston University for two years while simultaneously studying at St. John’s as a seminarian. After the completion of Third Theology, Americo took a pastoral year to get a full immersion into American culture and parish life. He was sent to St Rose of Lima Parish in Topsfield, and St Agnes Parish in Middleton full time from the spring of 2015 until his ordination to the Transitional Diaconate by Cardinal O’Malley on April 30, 2016. He was then assigned as a deacon to St. Mary’s Parish in Holliston, to serve until his ordination in May of 2017. Americo’s vocation is summarized in faith, prayer and service.

Deacon John BarryDeacon John Barry
Permanent Deacon, (photo left)

John Barry was ordained to the permanent diaconate on September 21, 2013. John grew up in Bristol Connecticut, the youngest of seven children. His parents (William and Jane) and his oldest sister (Kathleen Rose) are deceased. His brother Bob, also a deacon, currently serves at the Church of St. Patrick in Farmington, Connecticut. The great love and strong faith of his parents and siblings (Jane, Colleen, Bill, Mike and Bob) have helped to form John’s understanding of God’s infinite love for each of us.

After having received a degree in graphic design and illustration from LIU Southampton, John married Diane Grabowski on October 8, 1988. Moving to Massachusetts, John worked as a graphic designer at an architectural firm in Watertown for seventeen years. Settling in the Holliston area shortly after their marriage, Diane and John became active members of St. Mary’s parish.

In December of 2007 John received a master’s degree in Art Education from Framingham State University, and began teaching art at both the elementary and high school levels. John and Diane currently reside in Medway with their children Sarah, David and Nolan.

Deacon Martin Breinlinger 
Senior Deacon, (photo top left group)

Martin (Marty) Breinlinger was ordained to the diaconate in 1976, the first deacon class in the Archdiocese of Boston. His training took place at St. John’s seminary.

After ordination, Marty received a certificate in Pastoral Ministry from Emmanuel College. He has served at St. Mary’s since ordination. He and his wife, Mary Alice, were involved in family ministry for many years. Additionally he has been involved in the RCIA program, ministry to the divorced and separated, and religious education. Currently Marty is directing the Ministry to the Homebound.

Marty is retired from the Polaroid Corporation and currently teaches negotiation and mediation at Clark University in Worcester. He has been a resident of Holliston since 1966.