Lebanon's first high school in 1876 was in one room of the original Central School, located where the City Building is now.
In 1890 the school moved to the newly constructed Harney School, where the Elks Club is now located. Classes were conducted there until 1908 when the first high school building on North Lebanon Street was constructed.
In 1931, the final phase of a new high school building located on Meridian Street was completed. The two buildings were used until 1958 when the present building on Essex Drive was finally opened for classes.
In 1967, the physical education wing of the high school was complete. This included the gymnasium, swimming pool, and the auditorium. A new circular wing for the English classes was added in 1972.
In March 1990, a new phase of renovation was begun costing an estimated $16.5 million. The enhancements included new lockers, television monitors, computer labs, improved guidance and administrative offices, a new library, a new auxiliary gym, new tennis courts, additional classrooms, and improved traffic and security patterns.
The results of the renovations gave the high school the flexibility needed to grow into the future. The high school has since seen many changes through the years as the student population has grown. One thing has not changed at Lebanon High School though; it remains an outstanding environment for education.