Holy Cross Orthodox Monastery, Orthodox monastery in Castro Valley, California

Holy Cross Orthodox Monastery is a men's monastery of the Orthodox Church in America in Castro Valley, California, on a rural estate the monks bought in 1979 and largely built up themselves. A monastic chapel holds the services, and two monks live there. The community began with Archimandrite Theodor (Micka) and one disciple.

Archimandrite Theodor Micka was ordained a priest in 1965, the year his mother died and left him an inheritance meant for the monastery he planned. In 1970 he and a first disciple vowed to build a monastery dedicated to the Appearance of the Holy Cross over Jerusalem. In 1979 they bought a rural estate in Castro Valley with savings and the inheritance, and the monks did most of the building work themselves.

Services are held in the language most useful to those present: the monks can serve in Romanian, Church Slavonic, Greek or English. Great Vespers is sung on Saturday evening, and Sunday morning brings First Hour, Third Hour and Divine Liturgy, open to the public. Orthodox Christians of many ethnic backgrounds come for weddings, baptisms and other sacramental blessings.

Great Vespers is held on Saturday evenings, and First Hour, Third Hour and Divine Liturgy are celebrated on Sunday mornings; these services are open to the public. Other liturgical offices are reserved for the monks and may be attended only by special arrangement. Services are conducted in Romanian, Slavonic, Greek or English as the worshippers' needs require.

The monastery's full name honours the Appearance of the Holy Cross over Jerusalem, a dedication chosen by Archimandrite Theodor Micka and his first disciple when they made their vow in 1970. The monks did most of the building work on the rural estate themselves after buying it in 1979.