The school was founded in 1957 and named after Fr Hartmann SJ, a chaplain to the Pioneer Column who lived at St. George's College, Harare.

[3] In 1957 about 30 years after St George's College relocated to Salisbury (now Harare), it was decided to build a separate preparatory school on the newly acquired land near the Borrowdale Road.

Hartmann House has developed extensively with several buildings having been erected thereafter which included the recently completed Golden Jubilee Hall.

[2] The Grant of Arms was made by the Royal College of Heralds on 19 October 1931 and aimed to recognise three outstanding characteristics: The houses at Hartmann House are named after the four prominent Jesuits, who were among the founding fathers of St. George's College in Bulawayo.

Hartmann House has expanded its intake of pupils by incorporating Grade 0 to 7 in one preparatory school.