From 250 families at its founding in 1970, St. Mary's Parish community has grown to over 1,200 families in 2002. With All Saints, its summer mission in Ogunquit, St. Mary's has provided a spiritual home for residents and visitors alike. Visitors and newcomers to the parish comment on the warm, familial atmosphere of the parish.

In 1970 the population of Wells numbered 4,448 (including Ogunquit), and the parish rolls of St. Mary's (including All Saints) numbered, at most, 250 year-round families.

For more than a half century before St. Mary's became a parish, it was a summer mission of St. Martha's, Kennebunkport. "Old Wells-by-the-Sea," as the village was called, had churches of various denominations for their year-round members. Come Labor Day, however, Catholic residents had to travel to Kennebunk and Kennebunkport for religious services. "Old St. Mary's"  parish on Church St., Wells Beach, was built in 1920 and served as Mission and Parish Church from 1920 to 1980. The interior was winterized in 1957.

Rev. William J. Kelly, St. Mary's first Parish Priest, served as pioneer pastor from 1970 to 1977.

Rev. Paul E. Coughlin, St. Mary's third Pastor, served from 1987 to 1996. His personal charisma did much to inspire a sense of community in the parish. He oversaw the building of the present parish center, which is named for him.

Msgr. J. Joseph Ford was pastor at St. Mary's from 1996 to 2006. His deep faith and humility served as an inspiration to all who shared in the worship and spirit of St. Mary's. Fr. Joe, as he prefers to be called, was instrumental in keeping St. Mary's a growing, active and vital spiritual community.

Rev. Thomas Murphy became Administrator and spiritual leader of St. Mary's on June 20, 2006. With the merger of St. Martha's, Kennebunk, and St. Mary's, Wells, into Holy Spirit Parish, Fr. Tom became Administrator of the new parish on January 1, 2008.