Ainsley Gardiner fell in love with film while growing up in Whakatane on a diet of "movies, mostly really bad Hollywood movies". She thinks that diet helped give her an idea what makes a film "really good". It also fuelled a desire to work in the industry. Gardiner has gone on to seek out stories by two groups who have at times battled to be heard in the New Zealand screen industry: Māori and women. 

In 1995 Gardiner took the Avalon Film and TV production course, which included work placement with producer Larry Parr, who was running company Kahukura Productions. Though initially she wanted to write and direct, "there was a role for a producer, and it just naturally developed from there". Gardiner says that Parr "proactively promoted women and Māori. I've gotten to where I've gotten to because other Māori and women have actively fought so I don't have to experience prejudice and struggle, so I know there's an obligation on me to do exactly the same thing."

Parr handed Gardiner the reins to make her feature film debut with the low budget Kombi Nation (2003). She produced the road movie on the run across Europe, alongside director Grant Lahood. By then Gardiner had already produced some short films, including the offbeat The Hole (1998).

During her six years working with Larry Parr, Gardiner also co-produced 26-part series Lovebites, a serio-comic tale of Wellington 20-somethings inspired by big screen comedy Hopeless.

Gardiner had got to know actor Taika Waititi, who showed her some scripts, and told her of his aspirations to direct. Gardiner and Waititi would go on to work together on three award-winning shorts, and two features, one of which would become the biggest film then released on local soil.

Waititi's Two Cars, One Night (2003), produced by Gardiner and Catherine Fitzgerald, became the first Kiwi short to be nominated for an Academy Award for Best Short Film. Soon after making it, Gardiner formed company Whenua Films (initially Alo Films) with actor/producer Cliff Curtis. The production company was founded to encourage the telling of indigenous stories. In 2005, Whenua Films received a two-year producer overhead fund from the New Zealand Film Commission. According to Curtis, Gardiner has "an astounding capacity and capability, the amount of work that she does", and  provides worthy input on both the creative and financial fronts. 

The partnership of Gardiner, Waititi and Curtis began with a short film, World War II tale Tama Tū, which was invited to more than 40 festivals around the globe. Then came Waititi's feature film debut as a director, geek romance Eagle vs Shark, which was shot in five weeks. Gardiner described it as a tale of "two people who don't quite fit". Their follow-up movie would be "far better resourced and way more relaxed", even though the cast included 12 children, most of whom had no acting experience.

Boy revolves around an 11-year-old East Coast boy trying to make sense of his world. Though making it felt more relaxed, it was no walk in the park. Gardiner and fellow producers Curtis and Emanuel Michael had to deal with extensive location work in the Bay of Plenty, and a director who was also wearing two hats, playing a major acting role. 

Within four weeks of its 2010 release, Boy had grossed $4 million, pushing it ahead of Sione's Wedding as the most successful Kiwi comedy released on home soil. It went on to beat The World's Fastest Indian to take the number one spot for a local film by overall box office haul (at least until Waititi's Hunt for the Wilderpeople overtook it in 2016).

In 2015 Gardiner set up Miss Conception films with fellow producer Georgina Conder. The intention was to make films about women."I've also got three daughters," said Gardiner, "so I'm also interested in making movies that they will be interested in."

The duo kicked off in style with hit buddy comedy The Breaker Upperers, which both starred and was directed by Madeleine Sami and Jackie van Beek. Said Gardiner: "I loved that the characters were kind of anti-heroes,unorthodox female kind of role models, who are a little bit despicable, but actually loyal and loving." Miss Conception's second feature was documentary She Shears. It followed five female shearers working in a traditionally male world.

Earlier Gardiner had been a producer (with Mina Mathieson) on 2014 road movie The Pā Boys, which follows a band touring the East Coast and Northland, grappling with groupies and identity crises en route to Te Rerenga Wairua.

With Whenua Films, Gardiner also ran a Film Commission Short Film executive producer 'pod', overseeing production of a number of short films through the Commission's Short Film Fund. Among the shorts executive-produced by Whenua were Sima Urale's Coffee & Allah (2007 Venice Film Festival), Hawaikii (Berlin 2007), directed by cameraman Mike Jonathan, and Mt Zion director Tearepa Kahi's Taua (Edinburgh 2007, Clermont-Ferrand 2008).

In 2007 Gardiner and Kahi appeared as co-presenters of Iti Pounamu. The Māori Television series showcased critically-acclaimed Kiwi short films, and saw Gardiner interviewing those who made them.

Two years later she wrote and directed Mokopuna, a short film about a part-Māori girl who struggles to embrace her roots. The film took away the award for best short film at Canadian indigenous film festival Dreamspeakers.

Gardiner feels that her experience on anthology feature Waru helped change her approach to producing. Gardiner was one of a team of all female directors and writers on the film. She told Stuff's James Croot: "What I most enjoyed about Waru was how nine women could come together with different stories, different opinions and different viewers, disagree absolutely, but argue robustly and make decisions quickly." Gardiner argues that the film showed her "a way to really supercharge the creative process – allow people to be heard and come to an agreement".

Gardiner was one of the producers on variety show Happy Hour, featuring Temuera Morrison and Boy's Cohen Holloway. She was also an executive producer on acclaimed movie Fantail, written by and starring Sophie Henderson

In 2018 she was named a Member of the New Zealand Order of Merit, for her work in film and television.

Updated on 8 February 2019 

Sources include
Miss Conception Films website. Accessed 8 February 2019
Whenua Films website (broken link). Accessed 30 June 2016
Rebecca Barry Hill, 'The Woman behind Boy' (Interview) - The NZ Herald, 22 March 2010
James Croot, 'The Breaker Upperers: The Kiwi comedy breaking new ground for female-led film-making' Stuff website. Published 24 April 2018. Accessed 8 February 2019
Nick Grant, 'INTERVIEW - The constant Gardiner' - Onfilm, May 2006
Liam Maguren, "I Hope The Film Gets People Talking." Get to Know the Wahine Behind 'Waru' (Interview) Flicks website. Loaded 17 October 2017. Accessed 8 February 2019
'TBI Q&I: Ainsley Gardiner' (Interview) The Big Idea website. Loaded 25 March 2010. Accessed 8 February 2019