The budget airline announced today its adding flights to Napier, New Plymouth, Palmerston North and Nelson.
The four regional centres were chosen from a shortlist of seven destinations, with Rotorua, Hamilton and Invercargill missing out.
Air New Zealand followed suit offering $9 national fares on "grabaseat".
The national airline has said it won't be undercut in its home market.
Last Wednesday it said it would offer up to two million domestic fares under $100 and boost domestic capacity eight per cent this year.
"We are confident of our ability to stimulate the economy to fill those seats," chief executive Christopher Luxon said.
"We don't lose to Australians at home."
Transport Minister Simon Bridges and Economic Development Minister Steven Joyce were at Wellington Airport this morning where the announcement was made.
Jetstar will fly the Nelson-to-Auckland and Napier-to-Auckland routes from the beginning of December.
While New Plymouth-to-Auckland, Palmerston North-to-Auckland and Nelson-to-Wellington flights will take off from early next year with the first flight on February 1.
Jetstar Australia and New Zealand chief executive David Hall says the company's New Zealand management went to eight centres to make their decision.
"The feedback we’ve received from local councils, airports, economic agencies, businesses, and the tourism and travel trade has been invaluable in helping us to choose our first four destinations," he says.
Mr Hall says the four centres will help grow the market. It will also create 100 jobs for pilots, cabin crew and ground crew.
Despite Hamilton, Rotorua, Tauranga and Invercargill missing out this time, Mr Hall says the company will keep talking to stakeholders because they all want more airline competition.
Mr Bridges says the competition will help bring flight costs down for the regions and will be a boost for the regional aviation market.
The Qantas subsidiary currently flies Airbus A320 jets to Auckland, Wellington, Christchurch, Dunedin and Queenstown.
It will use five 50-seat Bombardier Q300 turboprops on the new routes.
The airline has a 17 percent share of the New Zealand domestic airline market, which is dominated by Air NZ.
Nelson Mayor Rachel Reese says the new route will open the city up to more domestic passengers, businesspeople and tourists.
"We encourage people from around New Zealand (and the world) to take the opportunity to come and visit our corner of the world. They may not want to leave," she says.
Business Central chief executive John Milford hopes the new routes and the extra people they bring to central New Zealand will help bring new businesses to the regions.
He thanked Jetstar for "showing great faith" in the regions.
Meanwhile, Labour says the Government should book their airfares like most other New Zealanders – by booking the "best fare of the day".
Transport spokesman Phil Twyford believes this would save money for taxpayers, while boosting services to regional New Zealand.
"Our heartland towns have a lot to gain from Jetstar's new services announced today and the Government could do its bit by pledging the tens of millions of dollars it spends annually really do go to the airline offering the best price.
"I challenge the Government to make the most of it – starting with a plan for public servants to always buy the best fare on the day."
Jetstar is launching the new routes with special one-way $9 fares. The airline's website briefly went down this morning following the announcement.
3 News / NZN
Great support for Nelson here from Mayor Rachel Reese http://www.3news.co.nz/business/jetstar-names-its-newest-nz-destinations-2015083109#ixzz3kX0NTDCC