Councillor Thomas Janke, who launched a campaign against the substance six months ago, said it was fantastic to see the work pay off.
The campaign was launched after hundreds of nitrous oxide canisters were found in Norbroom Park.
The town's litter picking group had been finding more as they tidied around the town as well.
Sergeant Dan Taylor, of Newport's safer neighbourhood team, said the partnership between police, councillors and the community had yielded fantastic results.
“Thanks largely to the joint efforts of the police, town councillors and the local community, the use of nitrous oxide in the Newport area has dramatically reduced," he said.
"This reduction has been achieved through education and regular patrols in target areas and is a great example of how working in partnership can achieve fantastic results for everyone living in Newport."
Councillor Janke said: "Six months on from my initial campaign, working in partnership with West Mercia Police, we have seen a real reduction in nitrous-oxide usage in our parks and public areas.
“It’s fantastic to see the hard work paying off. The campaign was taken onboard by the community despite following an initial dumping of hundreds of canisters on Norbroom Park in the early hours, only days after the campaign took off.
"However, through the determination of the community and Newport’s SNT, we are delighted to see this problem all but disappear from our public areas."
Tony Mercer, West Midlands health and wellbeing programme manager for Public Health England, warned about the dangers of using nitrous oxide.
"“The effects can include dizziness, confusion, loss of co-ordination, sound distortions and hallucinations," he said. "It is very difficult to judge how much you have used and the substance has been linked to a number of deaths."
Anybody with information about the supply or import of nitrous oxide for human consumption can call 101.
Alternatively, contact Crimestoppers anonymously on 0800 555 111 or at crimestoppers-uk.org