An extra flight will also be added to its Nelson to Tauranga route, which currently has two flights a week.
The new Nelson-Christchurch service will see Kiwi Regional Airlines (KRA) fly to the southern city twice a week.
KRA chief executive Ewan Wilson said it was an exciting time for the region.
"This is great news for Nelson. We can offer Christchurch for the first time. Nelson asked for a Christchurch service, the Nelson people asked and we delivered," he said.
Among the other changes KRA announced was a daily return flight between Nelson and Dunedin.
It will also fly four times a week between Hamilton and three times a week between Tauranga and Nelson. It started flying the Tauranga to Nelson route twice a week last month.
The new services will start on May 14.
The changes are being made due to high demand in regional centres, especially flights from Tauranga to Nelson.
"In the last six months, we have sold well over 10,000 seats, and we will continue to look at how we can best meet regional New Zealand's needs," Wilson said.
The airline has one 34-seat twin turbo-prop Saab 340A.
Wilson said he was "keeping his cards close to his chest" about whether he had plans to get another plane, and said further announcements about the fleet would be made in the next week.
Nelson's central location meant the airline considered the region an important location.
"Nelson is very much our hub ... We are providing regional air services that the travelling public is demanding," Wilson said.
"We are pleased that residents in many regional centres have responded so well to our airline."
KRA started operating in October flying routes between Nelson, Dunedin and Hamilton. It cancelled a route from Dunedin to Queenstown early on.
KRA also announced this year that it had partnered with Barrier Air which flies routes to Auckland, Kaitaia, North Shore and Great Barrier Island.
Increasing regional flights into Nelson will also help to boost and improve tourism for the district.
Nelson Tasman Tourism chief executive Lynda Keene said the expansion of the airline's regional air services was good news for Nelson.
"The fact that in the first six months of operation they have been able to evaluate which routes are working best and increase the frequency is really encouraging," Keene said.
"The Hamilton and Bay of Plenty catchment area is quite huge, it is really underrated, I think doing the direct links to and from Nelson is really going to grow for them."
Other airlines including Jetstar and Originair started flying to the regions last year.
Last updated 11:31, March 1 2016