After failing to win the seat, Ngarewa-Packer said she remained committed and would stay on as co-leader and run for the Te Tai Hauāuru seat again in 2023.
However, the final results threw up another scenario and Ngarewa-Packer said she is excited to be entering Parliament.
"I am shocked but thrilled to learn that with the final election results I will be joining Rawiri Waititi as a Māori Party MP," Ngarewa-Packer said.
"I can't wait to get stuck in to the mahi and for the opportunity to serve our people in Parliament – my commitment is that I will be an unapologetic champion for Māori.
"This has taken us by surprise. I was so focused on supporting Rawiri I wasn't even thinking of getting in myself.
"This shows how much energy and excitement our Māori Party campaign built – we've always done well on the specials but we've done even better than before.
"The Māori Party succeeded against all odds and swam against the tide, our people have sent a message that they want strong Māori voices who will fight for transformative policies.
"I am so proud of people for coming out in such strong numbers that we now have two Māori Party MPs. It is now clear that the Māori Party is back, and we are here to stay."
Waititi said in a statement he was looking forward to working with Ngarewa-Packer.
"We can now confirm that the Māori waka is back on the water and the next three years will be focused on building our movement together to ensure that my six other mates are on that waka with me come 2023," he said.
Ngarewa-Packer was brought up in Patea and educated at Tasmania and Stanford universities. She was deputy mayor of South Taranaki District in 2007-10.
In 2010 she became South Taranaki iwi Ngati Ruanui's chief executive, and in 2011 was asked to join the Government's Maori Economic Development Panel.
She has previously worked in radio and television, and in her Ngati Ruanui role has racked up years of experience in dealing with oil and gas companies.
