Justin-Siena is a Catholic, college preparatory high school in the Lasallian tradition which serves approximately 635 young men and women in grades 9 - 12. The School is located on forty acres in the City of Napa and in the Diocese of Santa Rosa. The school is accredited by the Western Association of Schools and Colleges (WASC) and the Western Catholic Education Association (WCEA). Justin-Siena serves a variety of students from Napa, Sonoma, and Solano Counties. In 1966 two schools opened on adjacent campuses--Justin High School (for boys) sponsored by the De La Salle Christian Brothers and Siena High School (for girls) sponsored by the Dominican Sisters of San Rafael. The schools merged in 1972 and were co-sponsored until the end of the 2005-06 school year when the Dominican Sisters transferred their sponsorship to the De La Salle Christian Brothers. Justin-Siena High School continues today as part of a world-wide network of almost a thousand Lasallian schools found in 84 countries. The School is administered by a President and Principal and is staffed by a dedicated community of De La Salle Christian Brothers, Dominican Sisters of San Rafael, and lay men and women.