Smokers of e-cigarettes could be fined up to $550 if caught vaping in public spaces or on public transport across NSW.
The ban will come into effect in July after state parliament passed new laws on Wednesday night.
"Put simply, where you are not allowed to smoke cigarettes, you now cannot vape either," Health Minister Brad Hazzard said in a statement on Thursday.
That includes shopping centres, cinemas, libraries, trains, buses, public swimming pools, near children's play equipment, sports grounds, public transport stops and outdoor dining areas.
NSW's chief health officer said there's evidence of potential health risks from e-cigarette vapours - even if there's no illegal nicotine in the e-liquid.
Vapours can contain chemicals, toxins and metals, and some of these substances, like formaldehyde, are known to cause cancer, Dr Kerry Chant said.
Cancer Council NSW welcomed the ban, which already exists in Queensland, Victoria, Tasmania and the ACT.
"It is great to see NSW government bringing NSW in line with other states," tobacco control manager Scott Walsberger said.
"There is conclusive evidence that e-cigarette vapour increases particulate matter and nicotine in the air which may be a risk to bystanders who are exposed to the vapour."
The new laws also force retailers to notify NSW Heath they are selling e-cigarettes.
Australian Associated Press
