St Jago was founded in 1744 under the will of
Peter Beckford (junior), one of the wealthiest planters in the
Colony of Jamaica. When he died in 1735, he had amassed a huge personal fortune, including the ownership of 1,737 slaves. St Jago was the third oldest school in Jamaica, after Wolmer's Boys', one of the
Wolmer's Schools (1729) and
Manning's School (1738). In the 18th century, these schools originated from their benefactors’ concerns for the education of the country's poor, usually the children of poor whites, as there was no system in place for the education of the children of slaves. It began as the Free School of St. Jago-de-la-Vega and later amalgamated two schools, Beckford and Smith (a boys' school) and Cathedral Girls High. Beckford, in his will dated 1730, bequeathed the sum of 1,000 pounds sterling towards the construction of a free school or hospital. The institution was intended to benefit the poor people of the town of St. Jago de la Vega, later renamed Spanish Town. Several other smaller endowments were made, resulting in the establishment of the St. Jago de la Vega Free School in 1744. A century later, Francis Smith, then Custos Rotulorum of St. Catherine, bequeathed 300 pounds sterling in his will dated 1830, for the founding of a school in the parish. Called the Smith's Charity School after its benefactor, it was opened in 1833. In 1876, this school was to merge with St Jago de la Vega Free School to form Beckford and Smith's Boys School. In 1956, the final merger to form the present day St. Jago High School took place. At that time, Cathedral High School for Girls was amalgamated with Beckford and Smith's Boys School and a new building housing the new St Jago High School was declared open in 1958 by then governor general of Jamaica, Sir Kenneth Blackburne. This property is commonly known as Ravensworth. == School crest ==