Colin Gregg, 75, is said to have indecently assaulted four boys aged between 10 and 14 over three decades.
Leeds Crown Court heard how Mr Gregg, of Gosforth, Newcastle, who helped build the family business in the 1960s, molested boys at his home, in his car and in a swimming pool.
He denies nine counts of indecent assault.
Paul Greaney QC, prosecuting, told the court Mr Gregg concealed his true nature behind a "veneer of respectability" and despite a life of distinction was "an abuser of children."
The allegations relate to a period when Mr Gregg was a teacher and head teacher, beginning in 1963.
He has dismissed the allegations as "evil lies" motivated by money.
The jury were told of Mr Gregg's time building up the bakery chain into one of the most recognised brands on the high street and of charity work in the north-east of England.
Mr Greaney said: "On the surface Colin Gregg deserves the respect and thanks of our community.
"The prosecution case is that he was an abuser and that during two periods 20 years apart, he engaged in the sexual abuse of boys."
The trial, which is due to last two weeks, continues.
The heir to the Greggs bakery business has gone on trial accused of sex offences against boys.