"These are people from the margins of society who, thanks to this charity, were able to recover from an appalling start and go on to live successful, productive and positive lives.
"What started as a small soup kitchen for the homeless and destitute has become one of the leading charities in this country helping ex-offenders to reform, resettle, and – critically- to break out of the costly and destructive cycle of reoffending."
The 31-year-old last visited the head office in 2009. He was a Patron of their 50th anniversary year in 2012.
The Kensington Palace statement said the Prince plans to "expand his work in the field of conservation particularly in respect of endangered species" and will "continue to expand his charities on issues relating to children and young people, veterans and serving members of the Armed Forces."
He will "continue to support the work of The Queen and the Royal Family through a programme of official engagements, both at home and overseas, with The Duchess of Cambridge," and over the next 12 months, will "work closely with the Royal Foundation of The Duke and Duchess of Cambridge and Prince Harry."