Parish Clergy

Rev. Mark J. Coiro, Pastor
Deacon John Barry, Permanent Deacon
Deacon Ronald Dowding, Permanent Deacon
Deacon Martin Breinlinger, Senior Deacon


Rev. Mark J. Coiro

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.

Deacon 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.

John has received master’s degrees in Art Education (Framingham State University) and Catholic Ministry (Theological Institute at St. John’s Seminary). He is retired from teaching Religious Studies at St. Bernadette Middle School in Northborough, and is now the Founder and Chief Designer for TopDog Design Studio in Medway. John and Diane have three children: Sarah, David and Nolan.

Deacon Ronald Dowding

Ronald (Ron) Dowding was ordained into the Permanent Diaconate on October 3, 2020. Ron grew up in Southwick, Massachusetts in the foothills of the beautiful Berkshires. He is the third of four sons of John and Dorothy Dowding.

Ron is a graduate of Northeastern University (B.S. in Business Administration and Certificate in Professional Writing). He also holds a Certificate in Software Engineering from Harvard University. Ron is employed as a software project manager. He is currently pursuing a Master’s degree in Ministry from St. John’s Seminary.

Ron married his wife, Jeanne, in 1987 and in 1991 they moved to Holliston. They have two sons – Andrew and Christopher. For the past 15 years, Jeanne has been a math teacher at the middle school in Holliston.  Ron and Jeanne have been active in several ministries at St. Mary’s for many years. Ron is a founding member of the St. Mary’s Knights of Columbus council and Jeanne was a founding member (secretary) of the WINGS ministry at St. Mary’s.

Deacon Martin Breinlinger

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.