The Holy Trinity Selenginsk Male Monastery, the first in Transbaikalia, was founded in 1683 by order of Tsar Feodor Alexeyevich by members of the Daurian Spiritual Mission of 1681. The head of the mission, Igumen Feodosiy, Hieromonk Makariy, and ten monks laid the monastery on the site of an old monastic building erected earlier by the Nerchinsk Cossacks. By 1684, the first church in honor of the Holy Life-Giving Trinity was built here. Over time, churches dedicated to Saint Archangel Michael, All Saints, and Saint Nicholas the Wonderworker appeared in the monastery.

The main goal of the monastery was to spread Christianity among the local peoples and provide spiritual support to settlers from Russia. Initially, the monastery was wooden with strong protective walls, serving as a powerful fortress. Later, the wooden structures were replaced with stone.

The monastery held significant administrative, cultural, and moral importance for the region. Being a stronghold of Russia beyond Baikal and located at the crossroads of roads from East to West and from North to South, it quickly developed and became the largest monastery of its time. Many notable religious and state figures visited it, such as the great-grandfather of A.S. Pushkin, A.P. Hannibal, the godson of Peter I, as well as the future Emperor Nicholas II Alexandrovich, who gifted the monastery a 'silver-gilded' altar cross. For a long time, Innokenty Irkutsky Kulchitsky lived in the monastery, awaiting his departure to China, and his spiritual mentor was Archimandrite Misail, a member of the Daurian Spiritual Mission. According to legend, a spring blessed by a saint has been preserved on the monastery grounds.

In 1920, the monastery was closed. During the Soviet era, it first housed a colony and later a psychiatric hospital. In December 2006, the entire complex of monastic buildings was transferred to the Russian Orthodox Church, and the revival of the monastery began.

The monastery occupies a vast territory surrounded by walls. Three churches have been preserved: the Trinity, Michael-Archangel, and Nikolsky, as well as various buildings remaining from the time when a psychiatric hospital was located here.

Regular worship services, church sacraments, and processions are held at the monastery. The monastic way of life is gradually being restored.

The brotherhood of the monastery is actively engaged in missionary, social, and youth activities.