Stars including Cate Blanchett, Elijah Wood, Barry Humphries and Hugo Weaving will tread the red carpet for the opening, the first instalment in a three-part prequel to Jackson's blockbuster The Lord of the Rings trilogy.
Hobbit fever has seized New Zealand ahead and the capital is dotted with giant sculptures of key characters such as Gandalf the wizard atop the Embassy cinema and a bug-eyed Gollum greeting visitors at the airport.
Images of British actor Martin Freeman playing the central role of Bilbo Baggins cover the entire facades of office blocks and have been plastered on everything from coins and stamps to the side of an Air New Zealand plane.
Freeman, acclaimed for his work in The Office and Sherlock, acknowledged his part as the hairy-toed adventurer in the much-loved JRR Tolkien children's story was the biggest of his career.
"This is proper, epic film making ... I don't know any actors, apart from those who worked on The Lord of the Rings, who've made a film that's this big or taken this long," he told the Dominion Post.
"I certainly don't think I'll ever do another film that's like, or as long, as this again."
The films, which were shot back-to-back with an estimated budget of $500-million, depict Bilbo's quest to reclaim the lost dwarf kingdom of Erebor from the fearsome dragon Smaug.
Bringing them to the screen proved a saga in itself, taking more than six years after the project was first mooted in September 2006.
Mexican filmmaker Guillermo del Toro was initially poised to direct, but quit in 2010 after years of delays due to legal wrangling between Hollywood studios over the rights to the book, forcing Jackson to take over.
When a green light to begin shooting was finally obtained, a union dispute threatened to move the production offshore—robbing it of its distinctive New Zealand backdrops—until the government intervened by changing labour laws.
Jackson was also struck down by ill health early in the shoot and as recently as last week there were allegations—strongly denied by producers—of animal cruelty and a US lawsuit filed by Tolkien's heirs over marketing rights.
Critics have also questioned whether a three-part saga is truly necessary given the original book stretches to just over 300 pages and suggested that box-office returns could have trumped artistic considerations.
At one point last year Freeman joked about a "Hobbit curse", but with Jackson's original Rings trilogy grossing more than $2.9-billion worldwide there was ample incentive to press on.
The Rings movies also garnered critical success, snaring a total of 17 Oscars, including a record-equalling 11 at the 2004 Academy Awards, when Return of the King took out best picture and best director.
The movies were also credited with spurring a tourist boom in New Zealand and turning its film sector from a virtual cottage industry specialising in art-house productions into a powerhouse worth $2.6-billion a year to the economy.
Tourism has stagnated in recent years and the industry is hoping the sweeping New Zealand vistas in the Hobbit will renew interest, marketing the country as "100% Middle Earth".
Amateur short filmmaker Shirley Jones said she would join the crowds at the Wellington premiere, not only to glimpse the stars but also to acknowledge the impact Jackson's adaptations have had on New Zealand.
"They've put us on the map and provided momentum for creative industries across the board, not just in film," she told Agence France-Presse.
Spectacular as the Wellington event promises to be, nature could provide an even bigger accompaniment as two North Island volcanoes used to depict the desolate wasteland Mordor in the Rings movies rumble ominously.
With uncanny timing, one staged a minor eruption last week and vulcanologists say both could burst to life at any moment.
The first Hobbit movie will be released globally in December. The second, The Hobbit: The Desolation of Smaug, is due in December 2013 and the final chapter The Hobbit: There and Back Again follows in July 2014. - AFP