Founded in 1956 by the late Vernon E. Simpson, Montclair College Preparatory School was one of the oldest private, co-educational, independent, secondary schools in the San Fernando Valley.

A rigorous, traditional college preparatory education was offered to students in grades six through twelve.

Montclair Prep maintained faculty academic advisement and standards committees that worked with the administration to maintain the highest caliber of academics and to provide a small group of social, athletic, and cultural extracurricular activities for its students.

In May 2011, Gazi Kabir, a social studies teacher, was arrested for having sex with a 15-year-old student on multiple occasions.

He was previously accused of misdemeanor in 2007, and his teaching certificate had been suspended for misconduct for two weeks by the California Commission on Teacher Credentialing.