The name was revealed to staff and students at 10.40am today.
Principal David Dodd said the merger of North Devon College with East Devon College meant both names had to go.
The college has worked with a company called Interbrand to come up with the new name, brand and logo.
Revealing the new name Mr Dodd said: "In a series of language and naming exercises, we explored perceptions of Devon, of the colleges and its people.”…
….Anticipating criticism that Petroc is a Cornish name, the college said in a statement: "Petroc is a Celtic name that has connections with Cornwall but even stronger links with Devon where the county's flag is dedicated to him.
"Cornwall's main patron saint is St Piran, whose flag is recognised as the Cornish national symbol.
"St Petroc was born in Wales but primarily ministered to the people of sixth century Dumnonia (now Devon, Cornwall and parts of Somerset and Dorset).
"He is one of Cornwall's patron saints but there are 17 churches dedicated to him in Devon, while there are just five in Cornwall....