In 1874 or 1875, the first school in the area was built by Frederick Sprague (later convicted in the murder of Thomas More) on the north side of the Santa Clara River near the current bridge. A few years later it was moved to the east bank of Sespe Creek just north of the railroad bridge.
Eventually grammar schools serving grade one through eight were established in Sespe, Fillmore, Willow Grove, San Cayetano and Montebello. These eventually became the Fillmore Union Grammar School District.
Up until 1910, students wishing to go further attended high school in Santa Paula. A temporary "high school" was established in a house built by Mrs. George (Hattie) King on the southwest corner of Second and Saratoga. The building still stands as a private residence. A permanent building opened in 1911 at Second and Central. It served as the high school until 1924 when a larger building was built at the site of the current high school. The 1911 building served as the junior high school until it was destroyed by fire in 1937.
In 1911, the first class graduated from Fillmore High School. It was comprised of four graduates, Mary Cummings, Albert Wiklund, Sarah King and Mabel Arthur.