Jamie Oliver's Fifteen Cornwall restaurant is closing with immediate effect, "following an independent financial review".
The restaurant near Newquay was run by charity the Cornwall Food Foundation (CFF), which trained unemployed people to work in its kitchen, in Newquay.
Earlier this year, Jamie Oliver's restaurant group went into administration.
Mr Oliver said he was "surprised and saddened" about the latest closure.
CFF chief executive Matthew Thomson, said: "I am profoundly sorry for the hurt, loss and distress this announcement will undoubtedly cause".
In a statement, CFF said: "As a charity and social enterprise restaurant we have welfare and safeguarding responsibilities that we are doing our utmost to resolve.
"We are talking with partners to find a way for the support for people to continue including those on the Fifteen training programme and Food for Change".
Oliver said he was "very surprised and saddened" to hear the restaurant had closed.
"Both organisations have always been run separately from us, but the team has done an amazing job with the trainee programme, training over 200 chefs and reaching so many more along the way - so this is a huge blow. My thoughts are with everyone affected," he said
Last month, the restaurant had announced it was searching for a new cohort of apprentices.