Moreau Catholic High School opened its doors in 1965 to a class of 103 ninth grade boys, temporarily located on the parish grounds of St. Bede's Church.

The school was constructed with financial and community support from the members of the Diocese of Oakland, the late Bishop Floyd L. Begin and the Brothers of Holy Cross, South-West province.

At the request of Bishop Floyd Begin, Moreau became a coeducational institution in 1969, with the admission of 177 ninth grade girls.

Bishop Allen Vigneron and Hayward Mayor Roberta Cooper officiated at the April 30, 2006 groundbreaking ceremony for a multimillion-dollar expansion at Moreau.

Moreau is a member of the Mission Valley Athletic Conference (MVAL), the North Coast Section (NCS), and the California Interscholastic Federation.