The new Mayor of London also suggested that building more boxing academies could help curb youth violence.
Speaking two days after the murder of 15-year-old schoolgirl Arsema Darwit – the 16th teenager to be killed in London this year – Mr Johnson said it was vital that the "root causes" of such crimes were addressed.
As well as tough action by police, youngsters needed a varied academic and physical education.
"I think there's a huge amount we can do in London by promoting the learning of languages including Latin," he said, who studied Classics at Oxford University.
"I would like to see not only that but I would like to see ancient Greek. Latin can help with all languages.
"The government want to encourage more kids from less advantaged backgrounds to top universities and that would really help them."
"And of course education is one issue to do with all the social problems."
Elsewhere (and presumably at the same press conference):
Boris wants to see Latin and ancient Greek recognised by the government for inclusion when the government is setting up language schools.
Who studied Latin, he asks. And who hated it? I can't see how many hands went up, but Boris insists the classics are great.
... and in yet another place, but at the same pc:
While backing the teaching of Latin in schools, a technical problem meant the audience could not hear Mr Johnson. He said: 'What's going on? Can you hear me? There we go... some anti-Latin gremlin creeping in there!'
... hmmm ... I wonder if promotion of Latin and Classics is going to be BJ's 'carthago delenda est' phrase ...