An undercover police operation, in which youngsters tried to buy knives and alcohol, saw every shop pass the test purchases.
Young people worked with police officers to visit 14 businesses in the city centre, Ecclesall Road and in Hillsborough last night.
They visited premises including convenience stores and pubs and all refused to sell knives or alcohol.
John O’Malley, South Yorkshire Police’s licensing manager, said: “The purpose of these types of operation are to identify any stores, organisations or businesses that aren’t abiding by the law when it comes to allowing under 18s to buy knives or alcohol. They are an incredibly important way of us keeping young people safe.
“Last night we visited 14 premises, from convenience stores to some popular discounters and pubs - they all passed, which is fantastic. It gives me a chance to say thank you to businesses and their staff for taking their responsibilities seriously.”
He added: “By running operations like this, it is a chance for us to watch how businesses carry out their responsibilities in reality.
“However, it’s not just a responsibility that lies with retailers. If you are shopping and you see a young person being sold a knife, or you’re in a pub and they’re serving people who are clearly underage, then we’d ask you to contact us.
“It sounds like a little thing, but it really can help keep teenagers living in our city safe.”