The Archdiocese of Denver () is a Latin Church ecclesiastical jurisdiction, or diocese, of the Catholic Church in northern Colorado in the United States.
It is part of the XIII Conference Region and includes 113 parishes, 307 priests, and an estimated 550,000 lay Catholics. The mother church of the archdiocese is the Cathedral Basilica of the Immaculate Conception in Denver. As of 2023, the archbishop of Denver is Samuel Aquila.

Area
The Archdiocese of Denver covers an area of . It includes the city/county of Denver and the following counties:

Adams, Arapahoe, Boulder, Broomfield, Jefferson, Larimer, Logan, and Weld.

It is the metropolitan archdiocese of its ecclesiastical province. The province includes three suffragan dioceses:
Diocese of Cheyenne
Diocese of Colorado Springs
Diocese of Pueblo
History
1860 to 1890
The first Catholic church in Denver was founded in 1860 by Joseph Machebeuf. It would later become St. Mary's Cathedral.
In 1868, Pope Pius IX erected the Vicariate Apostolic of Colorado and Utah, taking its territory from the Diocese of Santa Fe and the Diocese of Grass Valley. The pope named Machebeuf as the vicar apostolic. In 1870, Pius IX removed the Utah Territory from the vicariate, creating the Vicariate Apostolic of Colorado. The pope named Machebeuf as vicar apostolic.
While vicar apostolic, Machebeuf founded an academy and a school for boys in Denver, a convent of the Sisters of Loretto, St. Joseph's Hospital in Denver, the House of the Good Shepherd and the College of the Sacred Heart in Denver. The Catholic population of Colorado increased under his tenure from a few thousand to approximately 50,000. Sacred Heart of Jesus, the first Catholic church in Boulder, was dedicated in 1877. In 1878, Michaud funded the purchase of a wooden building in Fort Collins to become St. Joseph's, the first Catholic church in that city.
On August 16, 1887, Pope Leo XIII suppressed the Apostolic Vicariate of Colorado, replacing it with the Diocese of Denver, which covered all of Colorado. The pope named Machebeuf as the first bishop of Denver. That same year, the pope named Nicholas Matz as coadjutor bishop to assist Machebeuf. When Machebeuf died in 1889, Matz automatically succeeded him as bishop.
1900 to 1941
During his 28-year-long tenure, Matz made Catholic education his top priority, establishing dozens of parochial schools. He demanded that Catholic parents send their children to these schools under pain of mortal sin. In 1905, he founded St. Thomas Seminary in Denver, staffed by the Vincentians. He broke ground for the new Cathedral of the Immaculate Conception in 1902, later dedicating it in 1912. He also established thirty-four new parishes, a cemetery, and a diocesan newspaper. However, Matz met opposition from many priests and his ambitious building projects drove the diocese into a large amount of debt. He was a strong opponent of labor unions, especially the Western Federation of Miners.
After Matz died in 1917, Bishop John Henry Tihen of the Diocese of Lincoln was appointed bishop of Denver by Pope Benedict XV. During World War I, Tihen supported Liberty bonds and the National Catholic War Council, and organized students at Catholic schools as the U.S. Boys Working Reserve and the Children's Red Cross Campaign. Tihen was forced to defend the church in Colorado from the Ku Klux Klan, which he condemned as "an anti-Catholic and un-American society." He also supported women's suffrage and the labor movement, and founded The Denver Catholic Register in 1905. During his tenure, Tihen organized the diocesan Catholic Charities; increased the number of parochial schools from 31 to 49, and the number of priests from 174 to 229; dedicated 41 churches; and established Loretto Heights College in Denver, three hospitals, an orphanage, and a home for the elderly. Tihan retired in 1931.
In 1931, Urban John Vehr was appointed the fourth bishop of Denver by Pope Pius XI. Vehr soon visited every parish in the diocese, wearing out the new Studebaker automobile given to him by his clergy. The number of parishes in the diocese fell from 111 in 1930 to 87 in 1940 due to the Great Depression. Vehr cooperated with the New Deal programs of President Franklin D. Roosevelt, asking priests to celebrate mass at the two dozen Civilian Conservation Corps camps established in Colorado. He reorganized diocesan affairs and placed ownership of all parish properties in the name of the bishop.





