"Thank you, Kia Ora," said a slightly nervous Waititi as he accepted the Academy Award on Monday afternoon (NZ time).
He thanked his mother and dedicated the award to indigenous children around the world.
It is the first Oscar and third nomination for Waititi. He follows a string of New Zealand Oscar winners over the decades, including Peter Jackson, Jane Campion and Anna Paquin.
"Amazing. Thank you," Waititi said, holding the statue. "This is really light. It's supposed to be heavy," he joked, before thanking his mother "for being my mother and for, I mean, for many other reasons. For giving me the book I adapted. This film wouldn't have existed without you doing that."
He also thanked the film's producers, and said there were many others he wanted to thank but couldn't "remember them."
Among the nominees were also Anthony McCarten, nominated in the best adapted screenplay award for The Two Popes, and Tom Eagles is nominated for best editing for Jojo Rabbit.
Jojo Rabbit was up for six Oscars, including best picture.
Earlier this month, Waititi picked up a BAFTA and Writers' Guild Award for best adapted screenplay for Jojo Rabbit.
Prime Minister Jacinda Ardern said today that New Zealand is incredibly proud of the Kiwi filmmaker. She said she had seen the movie and enjoyed it.
South Korean social satire Parasite won the Oscar for best picture, making history as the first film not in the English language to win the movie industry's highest honour.
Parasite, about the gap between rich and poor in modern Seoul, won a total of four Oscars, including best director and screenplay for Bong Joon Ho and best international feature.
"I never thought I would win," Bong (50) said while accepting his best director Oscar. Paying tribute to his four fellow director nominees he said, "I would like to get a Texas chainsaw and split the Oscar into five and share it all with you."
The thriller, showing how struggling scammers insinuate their way into the life of a rich family, with dire consequences, was considered the front-runner going into the Oscars ceremony after winning the Palme d'Or at the Cannes Film Festival last year, as well as Golden Globe and Screen Actors Guild awards last month.
Bong beat Hollywood veterans including Martin Scorsese and Quentin Tarantino for his Korean language movie about the violent clash between haves and have-nots in contemporary Seoul.
In his acceptance remarks, Bong acknowledged both directors.
"When I was in school, I studied Martin Scorsese's films. Just to be nominated was a huge honour. I never thought I would win," he said as the audience rose to its feet in applause.
"When people in the US were not familiar with my film, Quentin always put my films on his list. He's here," Bong added. "Quentin, I love you!"
Renee Zellweger was crowned best actress at the Oscar for her portrait of Hollywood legend Judy Garland in Judy, a biographical drama exploring the singer's personal and professional turmoil at the end of her life.
It marked the second Oscar victory in four nominations for Zellweger (50), a Texas-born performer whose immersion in the role of Garland also earned Golden Globe, Screen Actors Guild and BAFTA awards.
The 50-year-old faced field of nominees that included Charlize Theron for Bombshell, as well as Scarlett Johansson for Marriage Story, Cynthia Erivo for Harriet and Saoirse Ronan for Little Women.
Admittedly intimidated at the notion of playing one of America's most iconic show business figures 50 years after her death, Zellweger embarked on extensive preparations to transform herself for the role. She took voice lessons for a year and worked with a choreographer to capture Garland's mannerisms. The movie focuses on a period when The Wizard of Oz star struggled with substance abuse, depression, insomnia, financial instability and a custody battle.
Her Judy performance was a far cry from the scrappy, plain-spoken farmhand she played in the epic Us Civil War romance Cold Mountain, a role that earned her an Academy Award for best supporting actress in 2004.
Phoenix (45) won the best actor Oscar after three previous nominations, crowning an awards season that has seen him sweep every major prize for his role in the standalone origin story of Batman's arch enemy.
The actor, known for playing brooding or emotionally troubled characters, dropped more than 22kg to play Arthur Fleck, an emaciated mentally ill clown who finds fame through a random act of violence in 1980s era New York City.
Accepting his award, he gave an impassioned speech about climate change and animal rights.
Dark and unsettling, Phoenix's Joker is far removed from the comic book characters traditionally seen on screen. Matthew Belloni, editorial director of the Hollywood Reporter, described it last year as "among the most chilling characters I have ever seen in film."
At the start of the awards held in Dolby Theatre, Brad Pitt and Laura Dern won their first acting Oscars.
Pitt capped a triumphant Hollywood comeback and was named best supporting actor for playing a charming stunt double in Once Upon a Time in Hollywood after having collected an armful of trophies earlier this year for the role.
"I'm a bit gobsmacked to tell you the truth," said the 56-year-old, who recalled his early days starting out as an unknown actor.
"Once Upon a Time in Hollywood - ain't that the truth?," he said, dedicating the Academy Award to his six children with former wife Angelina Jolie.
She dedicated it to her celebrity parents Diane Ladd and Bruce Dern. "This is the best birthday present ever," said Dern, who will turn 53 on Monday.
She received her first Oscar nod in 1992 for best actress in Rambling Rose and was also nominated in 2015 for best supporting actress in Wild.
American Factory, a Netflix film from Barack and Michelle Obama's nascent production house chronicling what happened to a group of Ohio autoworkers laid off during the 2008 recession, won the Oscar for best documentary feature.
The documentary, directed by filmmakers Julia Reichert and Steven Bognar, was the first release from Higher Ground Productions, a company the former US president and first lady formed in 2018 in a multi-year collaboration with the Netflix streaming service.
World War 1 movie 1917 won three Oscars, for its stunning "one-shot" feel cinematography, for visual effects and for sound editing.
Best original song went to Elton John and Bernie Taupin for Rocketman's "(I'm Gonna) Love Me Again".
Toy Story 4 was named best animated feature.
Netflix movie The Irishman, a costly Mafia saga directed by Martin Scorsese that had 10 Oscar nominations, came away empty- handed.
The Oscars ceremony, held without a formal host for a second year, started with a song and dance medley led by singers Janelle Monae and Billy Porter, and a surprise appearance by former hosts Steve Martin and Chris Rock.
Martin and Rock delivered a string of barbed jokes about the lack of female directors and people of colour among this year's nominees.
Rock pointed out Cynthia Erivo, who played slavery-era freedom fighter Harriet Tubman in Harriet and who was the only actor of colour nominated this year.
"Cynthia did such a great job hiding black people that the academy got her to hide all the black nominees," said Rock.
The nominees and winners are chosen by the 8000 members of the Academy of Motion Picture Arts and Sciences.
- NZ Herald and Reuters
