Trinity Episcopal Cathedral is the oldest church in the original city limits of Miami, having been organized by the Rt. Rev. William C. Gray on June 12, 1896, more than a month before the city was incorporated. Bishop Gray, a missionary bishop of the Episcopal Diocese of Southern Florida, had visited the Miami area in 1893, and had performed a baptism, confirmation, and celebrated Holy Communion in a schoolhouse in Lemon City, traveling up the coast from the Miami River on a launch provided by Julia Tuttle. Mrs. Tuttle, the "Mother of Miami", donated land at the southeast corner of 10th Street and Avenue B (now NE 2nd Street and NE 2nd Avenue) and in December, 1896, at that site a one-story, one-room wooden Trinity Church was completed as the first permanent church building within Miami's original city limits.

In 1904, the Trinity Mission became self-supporting and thus achieved parish status. The wooden church building was replaced in 1912 by an imposing, two-story stone church, similar in design to St. Paul's Episcopal Church in Key West. In 1923, as the great Miami and Florida real estate boom of the roaring twenties neared its peak, the congregation bought land at the corner of NE Bayshore Drive and 15th Street for the site of a church large enough to seat eleven hundred worshipers. Miami architect Harold Hastings Mundy designed the new church, whose construction was finished in July, 1925. The proportions of the building and its general idea were inspired by the Roman Catholic Church of St. Gilles, near Nimes in southern France. Muncy combined Romanesque, Byzantine, and Italianate elements of architecture to give the building a distinctive Mediterranean appearance.

When the boom collapsed in 1927, Trinity Church was saddled with a large mortgage debt, which was not paid until 1946, after almost twenty years of sacrifice and struggle. Today, because of the donations of many families and individuals, the interior of the Cathedral contains a profusion of finely wrought mosaics which depict the six days of creation, the hosts of heaven, and the Stations of the Cross. In addition, stained glass windows illustrate events in the life of Jesus with corresponding scenes from the Old Testament, the miracles of Jesus, the Song of the Three Young Men (the Benedictus), the seven sacraments of the church, and many of the saints and scholars of the British Isles before the Protestant Reformation. The Cathedral interior has a sound reverberation of more than four seconds, a feature which greatly enhances the musical effectiveness of the Cathedral's E. M. Skinner/Æolian Skinner pipe organ of fifty-six ranks and makes it one of the "warmest" rooms for music in the area.

In 1970, the delegates to the first convention of the new Episcopal Diocese of Southeast Florida voted to make Trinity Church the cathedral for the diocese, the location of the bishop's throne, the cathedra. In 1980, the Cathedral was judged to be of such architectural and historical significance that it was placed on the U. S. Department of the Interior's Register of National Historic Places.

In 2014, a “Jubilee Year” was declared by Bishop Leo Frade, which coincided with the completion of a massive restoration project, necessitated by a 40-year recertification requirement of the City of Miami, and the result of damage from numerous hurricanes and other storms that assailed the structure throughout the years.

The renovation and restoration of the Cathedral included repair and reinstallation of the Aeolian-Skinner organ, as well as the stained glass (along with impact resistant panes), replacement of the sanctuary and chancel floors, major structural repairs to the ambulatory, renovation of four floors of office space, and complete electrical replacement.

Also in this year the Jubilee Altar was created, with five crosses on its mensa representing the five Wounds of Christ. Embedded in the crosses are stones from places important to the history, life, and ministry of Trinity Cathedral. One comes from the Church of the Holy Sepulcher in Jerusalem, the most important shrine of Christianity. One comes from Canterbury Cathedral, the birthplace of Anglicanism. One comes from The Church of St. Gilles near Arles, France, upon which the architect patterned his ideas for the building of Trinity. One comes from The Washington National Cathedral, the home of the Episcopal Church and the seat of the Presiding Bishop. And one stone is taken from the foundation of the original St. Paul’s Church in Key West, the oldest church in our Diocese. The symbolism of these stones over time and space connects the people of Trinity and of the entire Diocese of Southeast Florida to the work of Christians around the world.

Like the cathedrals of old, Trinity is a place for contemplation, worship and ministry to the community. Today, Trinity Cathedral is a house of prayer for all people and its many programs and activities reach out to the community in numerous ways. The Cathedral congregation is ethnically and culturally diverse, making it a microcosm of the Miami community.