Jetstar is spending $50 million on a new aircraft and boosting its domestic and trans-Tasman services by 600,000 seats a year.
From November this year, the discount airline will introduce a ninth aircraft to its New Zealand fleet and increase services between the country's three largest cities, as well as flights from Australia to Queenstown.
The expansion means up to 36 extra weekly return flights on its domestic and trans-Tasman routes, creating 50 new jobs.
The new schedule delivers an extra 131,000 seats to Christchurch. However, the airline will scrap its five-weekly Christchurch to Queenstown flights and cut the Christchurch to Gold Coast and Melbourne services.
Jetstar chief executive David Hall says the airline is successful because it offers cheap flights to destinations where demand is high.
Mr Hall says the expansion takes its investment in New Zealand to $550 million over the past seven years and 500 jobs.
"We're see very strong potential to New Zealand - we're absolutely committed to the market."
Mr Hall says the expansion will give Jetstar up to a quarter of the New Zealand market.
Listen to David Hall on Checkpoint
Christchurch not entirely satisfied
The increased services mean 131,000 additional seats into Christchurch airport each year.
Chief executive Jim Boult says while the growth is welcome news, it is disappointing to see five weekly services suspended between Christchurch and Queenstown.
He says Christchurch is the busiest airport in the South Island and business is expected to increase as the earthquake rebuild gets underway.
Mr Boult says he is surprised Jetstar is not positioning to take advantage of that.