Many have taken to social media to express their surprise and sadness at the news.
Goodbye John Key! Legend of a PM! You will be missed!! The fact you resigned is just more proof of what an actually awesome guy u are and just how regular human being you are at the end of the day ππ Ka Pai!
Posted by Gracey Gee-lover on Sunday, 4 December 2016
While most simply have unanswered questions, including who will be the new Prime Minister and the reason behind Key's decision.
Residents in the Helensville electorate, where Key is the current MP, have also reacted to the news.
Huapai print shop co-owner Joan Hale is shocked by John Key's resignation.
Hale said her first comment upon hearing the news was: "Wow. He's playing into Labour's hands.
"I can't see why he's doing it now rather than later - having a new leader, and he's favouring Bill English, who doesn't seem to be that popular," said Hale, 61, of Whenuapai.
"If he's going to go it's the best time, I get that, [but] I think he would get in for a fourth term."
Ross Woodward, 77, of Taupaki, speaking at the Huapai shops, near Key's electorate office, was overjoyed at the Prime Minister's quitting.
"It wouldn't break my heart if I never saw him again.
"I think he's sold the country down the drain."
A few also took a moment to joke around on social media.
Some suggested the Prime Minister's DJ son, Max Key fill his father's shoes.
Others asked if Key would be helping his son record a new mixtape.
Over 1000 people have showed interest in a Facebook event to celebrate Key's resignation.
Jock Barr, 23, an outdoor sports instructor from Queenstown, said Key's decision was unexpected.
"I didn't even know how long he could be in for. It feels like he has done a good job though."
Brett Josephs, 50, a civil engineering contractor from Orewa, said he was quite surprised by Key's announcement.
"I did think he was going for a fourth term. I think he was a good prime minister."
Kathy Pearson, 48, a warehouse distribution manager and Kumeu mother of two, said Key's resignation held no meaning for her as she did not follow politics.
"From what I've heard from other people, it's probably a good thing. It needs somebody fresh.
"I don't think it's been that bad [with Key as prime minister]. I don't seem to have been affected by it too much. Work and Income need to pull their head in ..."
She would like to see Invercargill Mayor Tim Shadbolt become prime minister.
Huapai tattoo shop owner Emma Jenkins, 18, said of Key's resignation: "I think if it's for his family, it's a good reason.
"You should always put family first. He's done the right thing.
"A lot of people want him to resign, so it might be time for a new prime minister."
Some have dubbed the announcement "Jexit".