Trinity College is the oldest residential college of the University of Melbourne, the first university in the colony of Victoria, Australia. The college was opened in 1872 on a site granted to the Church of England by the government of Victoria. In addition to its resident community of 380 students, mostly attending the University of Melbourne, Trinity's programs includes the Trinity College Theological School, an Anglican training college which is a constituent college of the University of Divinity; and the Pathways School which runs Trinity College Foundation Studies and prepares international students for admission to the University of Melbourne and other Australian tertiary institutions, as well as summer and winter schools for young leaders and other short courses.

Trinity College was founded in 1870 by the first Anglican Bishop of Melbourne, Charles Perry. Students were in residence from 1872, the first being John Francis Stretch. The college was affiliated with the University of Melbourne in 1876. The Trinity College Theological School was founded by Bishop James Moorhouse in 1877, and the first theological student was Arthur Green.

In 1883 the college became the first university college in Australia to admit women when Lilian Helen Alexander was accepted as a non-resident student. With the establishment of the Trinity Women's Hostel (which later became Janet Clarke Hall) in 1886, Trinity admitted women as resident students, making it the first university college in Australia to do so. Among the earliest resident women was Classicist Melian Stawell.

In 1989 the Trinity College Foundation Studies program was established to prepare international students for entry to the University of Melbourne.

Since 2001, Trinity has also offered summer school programs to high school age students from around Australia and internationally. In 2010 the college hosted its first Juilliard Winter Jazz School.

Situated to the north of the main University of Melbourne campus, as part of College Crescent, Trinity's buildings surround a large grassed area, known as the Bulpadock. Its built environment is a mix of stone, stone-faced and brick, in a variety of styles from the different periods of its history.

The college's main buildings include:

The Trinity College Associated Clubs (TCAC) provides leadership for the annual orientation week program at the beginning of the academic year and facilitates a multitude of social, cultural and sporting events throughout the year. Trinity's clubs and societies run many different functions and events throughout the year. The current student clubs include an art room and the E. R. White art collection, Beer Budlay, Billiards Room, Dialectic Society (formed in 1877), a drama club, Environmental Committee, Games Society, Gender and Sexuality Alliance, Independent Dining Society, Racquet's Society, several music clubs and a wine cellar. Students also run an active program of social service and community outreach, including such programs as tutoring in local schools and educational visits to remote Indigenous communities.