The Catholic presence in what was then Oregon Country dates to the arrival in the 1830s of missionary priests François Blanchet and Modeste Demers from the British colony of Lower Canada.

This animosity, the warfare between the U.S. Army and the Cayuse and the failure of the diocese to grow prompted the Vatican to move Blanchet to safety in St. Paul in the Willamette Valley of Oregon.

In 1868, Francis X. Prefontaine requested Blanchet's permission to build a church near Pioneer Square in Seattle to support the city's first Catholic parish, Our Lady of Good Help.

[1] O'Dea guided the diocese through World War I and the anti-Catholic sentiment engendered by Initiative 49, a Ku Klux Klan-sponsored effort in Washington State to outlaw parochial schools.

[21] During his tenure, Connolly became known as a "brick and mortar bishop" for his construction of hundreds of Catholic facilities to accommodate the post-World War II population growth in the archdiocese.

[22] When Connolly retired in 1975, Pope Paul VI appointed Bishop Raymond Hunthausen from the Diocese of Helena as his successor in Seattle.

That same year, Pope John Paul II authorized Cardinal Joseph Ratzinger, prefect of the Congregation for the Doctrine of the Faith, to investigate Hunthausen.

Ratzinger appointed Archbishop James Hickey of the Diocese of Washington as apostolic visitor to go to Seattle and conduct the investigation.

[25] In response to Hickey's investigation, John Paul II named Reverend Donald Wuerl in January 1986 as an auxiliary bishop in Seattle.

[29] While some chancery officials expressed support for Wuerl, some questioned his role and saw little impact on the archdiocese a year after his appointment.

In February 1987, after appointing a commission to study the controversy in Seattle, John Paul II met with Hunthausen in Rome.

[30] According to Thomas Bokenkotter,"A resolution of the affair was finally announced by the Vatican in April after it accepted the report of a commission that recommended that Hunthausen's authority be restored and a coadjutor bishop be appointed.

[31] Hunthausen stoutly maintains that his archdiocese has remained fundamentally the same and was never in violation of Vatican doctrine; nor has he had to alter the general direction of his ministry or compromise his liberal beliefs.

"[32]John Paul II in May 1987 named Bishop Thomas Murphy of the Diocese of Great Falls-Billings as coadjutor archbishop in Seattle to assist Hunthausen.

[36] In 1992, Murphy opened Elizabeth House in Seattle, which provided medical care and job training for pregnant teens.

To help offset the declining numbers of priests, he provided financial support to a Seattle University program to train lay people in assist in some parish duties.

To replace Murphy, John Paul II named Bishop Alexander Brunett of Helena as archbishop of Seattle in 1997.

[38] Despite the economic recession, annual contributions from Catholics in Western Washington doubled during Brunett's tenure as archbishop, providing funding for the construction of St. Elizabeth Ann Seton Catholic High School, which opened in 2009 in Vancouver and Pope John Paul II High School, which opened in 2010 in Lacey.

[39] Brunett also helped launch the Fulcrum Foundation, which provides scholarships to poor families to send their children to Catholic schools and oversaw the $7 million purchase, renovation and expansion of the Palisades Retreat Center in Federal Way.

[43][44] On taking office, Etienne announced that he would not reside in Connolly House, the mansion for the archbishop of Seattle, suggesting it be sold to provide money to help the poor.

[51] The archdiocese in 2006 settled for over $1 million a lawsuit brought by two brothers who claimed to have been sexually molested by James Cornelius during the 1970s.

[53] In 2016, the archdiocese released a list of 77 priests, nuns and religious men with credible accusations of sexual abuse of minors.

[54] The archdiocese in 2018 paid a $7 million settlement to six men who had accused six priests, including Paul Conn and James McGreal, of sexually abusing them when they were minors during the 1970s and 1980s.

Ferguson said that the archdiocese had refused to cooperate in the state investigation into the use of charitable funds to cover up allegations of sexual abuse by clerics.