The band also claimed the Best Māori Group and Best Māori Songwriter awards.
Lead vocalist Joel Shadbolt, after winning the Best Pop Album award, said it was an "incredible" experience to be a finalist among so many other talented artists.
The Best Te Reo Māori Album award was won by Wellington band Grove Roots, which was formed by Noel Woods.
The Best Hip Hop Album by a Māori Artist award was won by Rei for his work on Hoea, which he said was his first te reo Māori project.
Rei also launched his new single, Borderline.
La CoCo is a Samoan-Māori music artist from South Auckland and she won Best R 'n' B Album by a Māori Artist in 2020 for her work on Grateful.
The Radio Airplay Song of the Year by a Māori Artist award was won by SIX60 for their song The Greatest.
A unique waiata combining the voices of Rob Ruha, Maisey Rika, Horomona Horo, Majic Paora, Troy Kingi, Ria Hall, Seth Haapu and Bella Kalolo, won this year's Radio Airplay Song of the Year by a Māori Artist in Te Reo award.
The song, Ka Mānu was composed by Rob Ruha.
The musicians worked together to record the song to support the Ihumātao land protectors.
The Emerging Artist Award Under 25 award was won by SIIAM (Sam Love) and the Emerging Artist Award Over 25 award was won by Teia Kennedy.
Accepting his award, SIIAM said: "I will leave you with this: Music can change the world because music can change people."
In the Iconic Awards category, Upper Hutt Posse founder Darryl Leigh Tomson (DLT) was the recipient of the Lifetime Contribution To Māori Music Award, recognising his work as a singer, songwriter, producer and mentor for many young Polynesian hip hop artists, as well as being an advocate for all things Māori.
The late Te Taite Kupa was the recipient of the Iconic Māori Music Composer award, recognising decades of work performing and writing songs internationally which continue to inspire new generations of Māori artists.
The 2021 National Waiata Māori Music Awards event will be held on September 10.