It follows a ban on military-style semi-automatic rifles and a nationwide gun buyback enacted shortly after the March 2019 killing spree by Australian national Brenton Tarrant, a self-avowed white supremacist.
Police Minister Stuart Nash said the legislation was an important step in making New Zealand a safer place after last year's "devastating" killings, the worst mass shooting in the country's modern history.
Girl students arrive to pay homage to the victims.
"But it does not define us, what defines us is the actions we took to stop such a terror attack happening again," he said.
Nash said the registry would finally provide police with data on how many firearms were in legal circulation, while the fit and proper person test would ensure gun owners were responsible enough to own a firearm.
Other changes include tougher punishments for illegal firearm possession and closing a loophole that allowed a foreigner like Tarrant to legally purchase an arsenal of weapons before the massacre.
The New Zealand Police Association said the legislation was long overdue.
"This law will, along with continued vigilance by police, gun owners and communities, mitigate the flow of guns into the hands of those who want them for criminal reasons," president Chris Cahill said.
Tarrant is being held in a high-security jail after pleading guilty to 51 charges of murder, 40 of attempted murder and one of terrorism.
He is yet to be sentenced because of delays in the court system caused by the coronavirus pandemic.