The OLA presence in Tanzania began in 1991, when the Irish Province founded a community in Mwamapalala, Isimiyu Region, in the Diocese of Shinyanga.
In 1994, a second foundation was established in Bugisi, Shinyanga Region, in the Diocese of Shinyanga. The sisters work in a health centre, teach in Buigisi Vocational Training Centre which grew out of a Women's Development Programme initiated by the OLAs, operate OLA Nursery/Primary School (English Medium), and engage in agriculture. In 2011 a postulate was built in Bugisi, the postulancy was later moved to Mwanza.
In 2005, a third foundation was established in Mwanza, Mwanza Region, in the Archdiocese of Mwanza as a base for mission and vocation animation.
Tanzania became a region, under the Irish Province, in November 2015. And in 2024 the OLA District of Tanzania was created becoming separate to the Irish District.