The first accident occurred about 2.30pm on Mt Aspiring Rd, after a woman lost control of her vehicle just before she crossed a cattle-stop.
She required hospital treatment for injuries she received to her left arm, Constable Bruce McLean said.
The accident was attended by Wanaka police and Wanaka St John.
In the second accident, a male motorcyclist received serious back and abdominal injuries after he fell from his Triumph motorcycle after crossing a cattle-stop on the Crown Range Rd, near Cardrona Bridge No 7, a sign-posted accident black spot.
The second accident also involved two cars and there would be an investigation to determine fault, Const McLean said.
All three vehicles were travelling north towards Cardrona.
The motorcyclist was following the two cars.
No-one else was injured in the accident.
Const McLean praised Downer EDI Works road worker Clive James, who was one of the first on the scene and was able call emergency services on his truck radio.
There was no cellphone coverage at the bridge.
The accident was attended by two Wanaka fire appliances and a Wanaka fire rescue tender, Wanaka police, Queenstown St John, a Queenstown-based helicopter from the Lakes District Air Rescue Trust and a Dunedin-based medical team and helicopter from the Otago Rescue Helicopter Trust.
