Chris Moore is to step down as chief executive of the Clink Charity after 11 years.
He will leave his role at the end of the year to take up a new position in the industry, which has yet to be announced.
Moore joined the Clink Charity in 2010, shortly after it was launched, and since then the group has trained thousands of prisoners to work in front and back of house hospitality roles, as well as in horticulture.
Research conducted by the Justice Data Lab and the Ministry of Justice in July 2019 found that prisoners participating in the programme were 32% less likely to reoffend.
Finlay Scott, chairman of the Clink Charity, said: "It is with regret that we announce the departure of Chris Moore as chief executive of the Clink Charity.
"Chris has taken the Clink from a single start-up training restaurant to being one of the most effective organisations reducing re-offending in the UK.
"On a personal note, I will miss Chris as both a friend and a colleague. He leaves the Clink in a very strong position having restructured the organisation to continue its brilliant work after he has gone."
Moore said: "After 11 years with the Clink Charity I have decided that now is the ideal time for me to step down as chief executive and I believe that the Clink is in great shape financially and operationally after the pandemic, with an exciting period of growth ahead for my successor to take the charity onto the next stage.
"I am immensely proud of what we have all achieved as a team and what our students and graduates continue to achieve daily. None of this would have been possible without the generosity of our funders, suppliers, supporters, customers, the Clink team, directors, trustees and HMPPS. I would like to thank them all for their help and support over the years.
"Over the years we have brought the issue of high reoffending rates into sharper focus and ultimately proved that by delivering a sector-led integrated training programme in partnership with Her Majesty's Prison and Probation service you can repair society by reducing reoffending and also support the hospitality industry that has a major skills shortage, with highly trained, work-ready men and women when they leave prison."
Moore said that his new role will involve working with "those in society that sometimes get overlooked".
He added: "The Clink has, and will, continue to demonstrate what can be achieved when society collectively engages to help those who want and deserve a second chance; it has been an honour to be able to play a part in that."
Earlier this year the Clink and New Futures Network announced a new inmate hospitality training scheme that will be adopted across more UK prisons. The Clink Kitchens will deliver training in up to 70 prisons over the next three years, enabling up to 2,000 men and women to achieve qualifications in hospitality and gain employment on release. The number of students on the programme will also increase from 220 to 800 a day.