Southside High School (1924-2014), located at the corner of Pennsylvania Avenue and South Main Street, opened in January 1924. The school had been opened to alleviate overcrowding at Elmira Free Academy, the Elmira City School Districts original high school. The district was divided so students living on the north side of the river attended Elmira Free Academy, with students living on the south side as well as the, as well as the towns of Southport, Ashland, and Chemung attending Southside High School.
From 1924 to 1945, the two high schools had one combined athletic program. From 1946 on, they had their own sports teams, the Hornets. Their school colors were green and gold. Since 1935, the school yearbook has been known as The Edsonian, in honor of the school’s first principal, Frank M. Edson. The school newspaper is called the El-So-Hi.
In 1979, Southside High School moved to a new building at 777 South Main Street, the site of the old Remington Rand plant. The new building was larger with more amenities including a swimming pool. In 2014, Southside High School merged with the Elmira Free Academy to form the Elmira High School, located at 777 South Main.