A million-dollar barramundi is the main lure in a Northern Territory Government campaign to attract tourists to the Top End during the low season.

The campaign, launched by NT Chief Minister Adam Giles, will see 76 barramundi tagged and released across fishing locations in the Top End, one of them carrying a $1 million prize tag and the remaining 75 carrying $10,000 cash prize tags.

Mr Giles said he hoped the Million Dollar Fish competition would generate "invaluable national and international exposure and put the Northern Territory on the global map as the place to come to fish".

"The Northern Territory has some of the best fishing in the world and the chance to catch the iconic Territory barramundi is one of fishing's greatest challenges," he said.

"Now that challenge comes with the potential of a $1 million reward," he said.

The campaign, fronted by former Australian cricketer Matthew Hayden, is being conducted in partnership with a gambling company, outdoors equipment retail chain, brewery, travel company and airline.

Low season in the NT stretches from October to February, and anglers are being encouraged to travel there with their families.

"About 40,000 interstate visitors come to the Top End for fishing every year but we want to encourage even more people to stay, play and fish," Mr Giles said.

He added the campaign was part of the Government's plan to drive the development of North Australia and "build a $2.2 billion visitor economy by 2020".

The Million Dollar Fish competition will run from October 1, 2015 to February 29, 2016.

It will run alongside a 2013 campaign, Do the NT, which Tourism NT said "challenges the barriers like distance, price and accessibility which can make consumers hesitate to book a Territory holiday".

In February, the Government imposed new NT fishing catch limits to prevent overfishing, with the changes backed by both amateur fishing enthusiasts and commercial operators.