The school was named after Jesse Ketchum, an entrepreneur and philanthropist in Yorkville in the 19th century. Ketchum had previously donated land in 1832 for a school which was built at McMurrich Street and Davenport Road. Overflow from this original 1832 school meant that girls were taught across the street at Ketchum Hall, a Temperance Hall built by Ketchum. In 1856, he donated the land for the current site to build a ‘Free and Common School.’ In 1858, a four-roomed school was built on the site and accommodated both male and female students. However, soon overcrowding became an issue and Ketchum Hall was once again used for overflow. In 1875, two rooms were added, and in 1878 a three-story addition was built. Yorkville Trustees bought the land to the west of the school to use as a playground. In 1883, Yorkville was annexed to Toronto and the Board voted to rename the school “Jesse Ketchum School.” In 1889, the first two-room addition (from 1875) was replaced with 8 rooms. A fire in 1904 destroyed part of the additions, but the main building was largely undamaged. Construction on the current building began in 1915 but was delayed due to the First World War. In 1917, the Recruits Deport of the Royal Flying Corps used the school building as a barracks, and the neighbouring park as a parade and sports ground. The building returned to school use in 1920. In 1958, the school accommodated approximately 1000 students in 31 rooms. That year, a major expansion was built upon the 1915 building, which added a gymnasium, assembly room, art room, science room, cafeteria, music room, speech and drama room, and new lighting. The formal opening of the renovated school occurred on September 29, 1958. New staircases replaced the originals in 1971. Today, the school accommodates around 450 students from Junior Kindergarten-Grade 8.