The school started as Ripley Hospital, founded by Julia, wife of Thomas Ripley, a merchant who traded out of Lancaster and Liverpool. Thomas Ripley was born in Lancaster in 1791, and had been an apprentice to a grocer and linen draper. Since his mercantile career began later than 1807, whether Thomas Ripley was associated with the slave trade is open to speculation as the slave trade was not fully abolished in Britain until 1833. He was likely involved due to the nature of his mercantile work and how commonplace slave trading was during this era.

Indeed, much of his wealth stems from the fact that he was one of the first English merchants to embark on trade with China, and much of his subsequent trade was with the East Indies. As a devout Christian, he was keen to establish a charity hospital, modelled on the Liverpool Blue Coat School. Having no children, on his death in 1852 he left a considerable sum of money in trust to establish the Ripley Hospital to cater to fatherless children, especially those whose fathers had been lost at sea.

On 3 November 1864, it was designated to educate an equal number of boys and girls – 300 in total – providing they lived within either 15 miles (24 km) of Lancaster Priory or 7 miles (11 km) of Liverpool Cathedral.

In September 1996, Ripley was designated a Language College..^[2]

The headteacher is Ed Goddard, who replaced Catherine Walmsley in 2017.^[3]

The farm has been the subject of media attention,^[when?] with features from BBC North West Tonight, BBC Songs of Praise and Newsround, all of which praised the school on the 'Farm to Fork' initiative, as the farm provides produce for the school kitchen. The school appeared on CBBC's Blue Peter on 6 September 2012, with the programme also focusing on the 'Farm to Fork' initiative.^[4]

Ripley St Thomas has been approved as a Technology college, adding to the Language status. This means students must take at least one language and at least one technology course, e.g. Food Technology or Mechanical Technology at GCSE, continuing the curriculum students experience from Year 7.^{[citation needed]}

In January 2012, an Ofsted report rated the school overall as "Outstanding", the highest of four achievable Ofsted grades. The grade of "Outstanding" was also assigned in all 33 of the areas assessed by Ofsted.^[5]

In December 2022, an Ofsted report rated the school overall as "Outstanding", the highest of four achievable Ofsted grades. The grade of "Outstanding" was also assigned in all 33 of the areas assessed by Ofsted, this was after Ofsted made changes to their policy.^[5]

In 2017, the Music Department was awarded the Music Teacher Awards for Excellence's award for Best School Music Department.^[6]

Ripley St Thomas achieves outstanding results for GCSE and A level students every year, far outweighing the local authority and national average. The results for 5 or more A* to C including English and Maths has risen from 85% in 2010, to 89% in 2011, 31% higher than the national average.^[7]

On Sunday 1 May 2011, Ripley St Thomas became the third high school in Lancaster to be granted Academy status by the Secretary of State, and was re-designated as "Ripley St Thomas Church of England Academy". The company has been registered with Companies House and an Academy Trust has been set up to run the company.^[8]

• Ripley School Chapel