Radio New Zealand Pacific reports that more than 100 guests gathered in Cornwall Park in Mt Eden at the weekend to celebrate the event, with cultural displays and dancing.
The event was organised by the New Zealand Papua New Guinea Business Council, whose chairperson is Andrew Wilson.
"We've had a wonderful event here which has been a celebration of PNG's 47th birthday, the 47th anniversary of PNG's independence from Australia," said Wilson.
"We had around a hundred people here with some nice speeches and some lovely cultural dancing from the wontoks.
"It was a cross-cultural event and we all had a nice time, our first time together after Covid. It's good to see everyone again."
September 16 marks Papua New Guinea's 47th year as a sovereign nation after it gained independence from Australia in 1975.
Unlike many former colonial territories around the world whose independence movements were forced or marred by violent upheavals, Papua New Guinea's transition towards independence was largely peaceful and met little opposition by Australia.
However, Australia's colonial past is still marred by injustices such as the White Australia Policy which treated Papua New Guineans as second class-citizens.
Papua New Guinean expat, Genevieve Mautu, says Independence Day is more a celebration of her country's diversity than a memorial of historical struggles.
"It marks the day we gained independence from Australia and regardless of what happened, we still have close ties with Australia. Many of us study and work in Australia," she said.
"It's become more of a celebration about PNG's diversity and celebrating our different cultures including people who are from overseas and who live in PNG. There are over 800 dialects and languages, and I just love that everyone speaks a different lingo."
According to the 2018 New Zealand census, the Papua New Guinean population accounts for 1131 people, while trade accounts for $NZ257 million.
Mautu said there are several Papua New Guineans who study in New Zealand.
"We formed a community group called the Wontoks of Aotearoa.
"We get together, we have a laugh, we have picnics, we share stories and jokes. It's about having a laugh and a good time like all other Pacific Islanders."