Reginaldo Francisco del Valle was a 19th-century California state senator who was instrumental in forming Los Angeles State Normal School, the predecessor to the University of California, Los Angeles (UCLA), and who, as a Los Angeles city water commissioner, was a leader in bringing water from the distant Sierra to the city.
Del Valle was born on December 15, 1854, in an adobe house facing the Plaza in Los Angeles, the son of Ygnacio del Valle of Compostela, Jalisco, Mexico and Ysabel Varela, who was born in California. In 1861, the family moved to Rancho Camulos in today's Ventura and Los Angeles counties.
A 2006 study of del Valle headed by David E. Hayes-Bautista reported that: "Young Reginaldo was tutored at home, becoming fluent in English and French as well as Spanish." He went to St. Vincent's College in Los Angeles for high school (1867–71) and, after graduating with honors, attended Santa Clara University, where he graduated in 1873. He read law with the San Francisco firm of Winans and Belknap, and he passed the state bar examination in 1877.
Del Valle opened his law office at 38 Temple Block, just a few steps from the Plaza. He was noted as a "logical and concise speaker" in an accent "with just a suave hint of Castilian."
On September 2, 1890, in San Francisco, he married Helen M. Caystile, widowed six years previously from T.J. Caystile, co-owner of the Los Angeles Daily Times, and adopted the Caystiles' daughter, Helen. The new couple had another daughter, Lucretia del Valle, who married Henry F. Grady of San Francisco.