The Universidad de Sta. Isabel (USI) is a private Catholic Vincentian university owned and run by the Daughters of Charity in Naga City, Philippines. It was established by the first five Daughters of Charity that arrived in the country (Philippines) in January 1868 with Bishop of Caceres, Most Rev. Francisco Gainza, O.P., initially as Colegio de Sta. Isabel, through the royal order of Queen Isabella II of Spain.

Colegio de Sta. Isabel was inaugurated on April 12, 1869 and became the first normal school for women in the Philippines and Southeast Asia. It achieved university status in 2001.

In the 1970s, the Community Extension Services (CES) started its community outreach programs. This social arm of USI was primarily the venue for students' field practice of which beneficiaries include the poor and marginzalized children, youth and adults in 8 barangays of Naga City. This later evolved into an opportunity to get involved in community welfare activities, particularly evangelization, non-formal education, socio-cultural education, small-scale income generating projects, health, nutrition and volunteer services. Currently, CES emphasizes Community Extension, Instruction and Research in their goal towards the improved quality of living and empowerment of the poor.

The main campus of the Universidad de Sta. Isabel is located at Elias Angeles Street, Naga City. Its annex campus is located at Panganiban Drive, Naga City.