The first Mass said in what would become the state of Vermont was celebrated in 1666 by a Sulpician priest from Montreal, in the chapel of Fort Sainte Anne on Isle La Motte.

[2] The northern region of Vermont was largely settled in the 18th century by Catholic French Canadians who migrated south from the British Province of Quebec.

During the late 18th century, out of convenience, the bishops of Quebec continued to minister to Catholic settlers and Native Americans, mainly in northern Vermont.

Around 1818, Marie Migneault from Chambly, Quebec, came to Vermont and ministered to the settlers by Lake Champlain for several years.

His territory extended from Rutland, Vermont in the south to the Canadian border in the north, a distance of about 100 miles (160 km) and from Lake Champlain in the west to the Connecticut River in the east.

[2] He usually made his headquarters at Rutland or Middlebury, Vermont, but spent most of his time traveling the state as a missionary.

[12] In 1892 De Goesbriand purchase land at Fort Sainte Anne on Isle La Motte in order to preserve its history.

[13] That same year, due to his age and failing health, he requested the appointment of a coadjutor bishop by the Vatican to assist.

Pope Leo XIII appointed Michaud, then pastor of a parish of Bennington, Vermont, to this post.

De Goesbriand spent his entire family fortune constructing churches and orphanages in the diocese and assisting the poor; he died with only four dollars left to his name.

He built the Fanny Allen Hospital in Colchester, Vermont and staffed it with nuns from the Religious Hospitallers of St. Joseph.

In 1905, the Daughters of Charity of the Sacred Heart of Jesus came to Newport, Vermont, to open a mission, where they served as teachers, nurses and catechists.

In 1910, Pope Pius X appointed Joseph Rice, then pastor of St. Peter's Parish in Northbridge, Massachusetts, as the new bishop of Burlington.

In November 1925, during a period of anti-Catholic agitation throughout the United States, the Ku Klux Klan burned a cross on the steps of St. Augustine's Church at Montpelier, Vermont.

After Rice's death in 1938, Pope Pius XI appointed Matthew Brady from the Diocese of Hartford as his replacement.

Brady erected 12 new parishes in Fairfax, Gilman, North Troy, Orleans, and South Burlington, all in Vermont.

In 1945, Ryan purchased a 7 acres (2.8 ha) parcel adjacent to St. Joseph's orphanage and created the Don Bosco School for delinquent boys.

[23] Faced with a shortage of priests in Burlington, and a decline in weekly mass attendance, Angell consolidated Sacred Heart and St. Francis de Sales Parishes in Bennington as well as St. Cecilia and St. Frances Cabrini in East Barre, and closed Our Lady of the Lake in St. Albans.

In 2018, Coyne announced that the diocese was selling the Cathedral of the Immaculate Conception due to a long period of low attendance.

[29] McDermott was Coyne's vicar general, and with the former's move to Hartford, served as Burlington's Diocesan Administrator.

Over 100 former residents stated that they had been physically, sexually and emotionally abused by nuns, priests and lay staff workers from the 1940s through the 1970s.

[21] Lawyers for the diocese originally asked the court to dismiss the St. Joseph lawsuits, on the grounds that the victims' allegations could not be corroborated.

Five priests who served as chaplain at St. Joseph's were also accused by victims of sexual abuse in unrelated litigation.

On September 30, 2024, the diocese filed for Chapter 11 bankruptcy, citing increased sex abuse lawsuits.

[31] In 1994, the diocese was sued by Michael Gay, who claimed to have been sexually molested by Reverend Edward Paquette during the 1970s.

[34] In February 2010, the diocese announced that it would sell its headquarters in Burlington and Camp Holy Cross in Colchester to pay sexual abuse victims.

[39] In May 2022, the diocese settled a lawsuit brought by a man who claimed to have been sexually assaulted by Roger W. Carlin.

The plaintiff, filing the lawsuit in 2021, said that Carlin abused him at St. John Vianney church in South Burlington between 1966 and 1967.

As of 2023, the Diocese of Burlington had a Catholic population of approximately 110,000, with 36 active priests, 44 permanent deacons and 15 religious ministering in 68 parishes.

"[47] An insurance company has estimated that it would cost $400 million to replace the physical assets of the diocese, including churches, schools, and nursing homes.