NSW Deputy Premier John Barilaro landed in Coffs Harbour to officially open the recent upgrade to the state's second busiest regional airport.

The $6.5 million upgrade, with $5.1m from the State Government's Restart NSW Regional Tourism Infrastructure Fund and $1.4m from Coffs Harbour City Council, enlarged the aircraft parking apron and taxiways to accommodate up to five jet aircraft.

It also financed more check-in counters, airline offices, staff facilities and airline lounges have been finished in the expanded departures area.

While in arrivals, an extra baggage carousel and toilets have been installed.

Mr Barilaro said the funding was part of a broad $70 million investment in improving regional airports around the state.

He said it was important to match infrastructure upgrades with the rise of the region's population.

"Coffs, the Mid North Coast, is a region that has seen significant growth," Mr Barilaro said.

He said the apron upgrade would allow the airport to cater for larger planes allowing airlines to upgrade services or attract new carriers.

"They say if you build it they will come," he said.

Mr Barilaro said the upgrade also set Coffs Harbour up for the decentralisation of government jobs.

"This really sets up Coffs Harbour for the future," he said.

Coffs Harbour Mayor Denise Knight said the upgrade was needed as the the airport headed towards catering for half a million passengers a year.

"Last year, the airport passed the 400,000 passenger mark - an all-time record - and will reach 420,000 by the end of this financial year," Cr Knight said.

"Now that these upgrade works have been completed, the airport will be able to process over 1000 passengers per hour during the busiest times."

Cr Knight said the council had spent more than $10 million in improving the airport over the last five years, including a $7.5 million upgrade to the main runway.