"It's wonderful to celebrate the completion of the site with those who have helped us get this far and welcomed us into their community," he said. "Launch Complex 1 presents a considerable opportunity to change the frequency of access to space."
Wairoa mayor Craig Little said it was exciting to see everything was finally coming together.
"It's quite exciting, it's been a long time coming," he said. "It's always been so positive for Wairoa, and once rockets start blasting off from there I think we'll start seeing some positive spinoffs."
During construction of the Onenui Station site, Rocket Lab used local contractors and suppliers whenever possible.
They will be among the nearly 200 local officials at the site's opening this morning, as well as members of the newly formed New Zealand Space agency, Rocket Lab's team and customers.
Facilities at the complex include a vehicle processing hangar where the rocket will be prepared for launch, and a 50-tonne platform standing over 15m tall, which will tilt forward to lift the rocket into launch position.
With a dedicated launch priced at $7.6 million, Electron is the most affordable small satellite launch vehicle. Customers signed to fly on Electron include Nasa, Planet, Spire and Moon Express.
It will carry satellites featuring a range of services - from improved weather reporting, internet from space, natural disaster prediction, and up-to date maritime data.
The company is currently working through the qualification of the first stage of the Electron rocket and hopes to begin the test flight phase once qualification and launch licensing are complete.