Pacifica has had its humble beginnings with its relatively small area. Before it was made up of the structures present today, the area which Pacifica resides on now was once a swine (pig) farm with strawberry fields surrounding it (hence the Strawberry Festival the City of Garden Grove hosts every year).

On September 5, 1965, Pacifica High School opened its campus to new students. The school year of 1965-1966 comprised of freshmen, sophomores, and juniors, but no seniors. There was no graduating class of 1966. The senior class of 1967 graduated with over 400 students.

Mr. Al Buenafe was the campus layout designer, and he became its first principal. He guided the school through its first two years before Mr. Ron Walter took his place in 1977. Already Pacifica was growing and coming alive in its education and leadership.