The school moved to new facilities at 451 West 20th Avenue in San Mateo in the fall of 1955 when the student body grew to 576.

[4] Phase I of Serra's master plan was completed in 2005, featuring new facilities for football, baseball, and wrestling, along with a 150-space parking structure.

Phase II was completed in 2011, and created five new science lecture-labs, a new music room, two art classrooms, an academic resource center, and a 550,000-gallon infinity pool for competitive aquatics.

In 2016, Serra undertook a smaller project, renovating the playing surfaces used for baseball, football, soccer, lacrosse, and track.

For a time in the years after World War II, the San Mateo school offered just three sports: football, basketball, and baseball.

As time went by, the Padres became one of Northern California's signature prep sports entities and the league itself morphed into a state powerhouse.

As of early 2018, the school had won 67 West Catholic Athletic League varsity titles, 31 Central Coast Section championships, and two state crowns (basketball in 2016 and football in 2017).

Brady and Swann, an all-American at USC and a member of the Pro Football Hall of Fame, were both Super Bowl MVP's.

One of the most dominating exhibitions by a Serra football team occurred in 2017 when the Padres, coached by Patrick Walsh, posted an overall 13-2 record (10-0 vs. West Catholic Athletic League opponents, a feat never accomplished before in the history of the league) and won a California Interscholastic Federation state championship, the first for a San Mateo County high school football team since 1926.