Residents reported the vegetation fire on the Heathcote Valley side of the Lyttelton Tunnel about 11am on Monday.
A Fire and Emergency NZ spokesperson said four engines and three helicopters were called to the scene.
The choppers were dousing the fire from the air. About 2pm, a firefighter at the scene said the blaze had been contained.
But he said the helicopters will remain at the site until about 3pm to manage any hotspots or flare-ups.
Four fire crews from the Woolston, Spreydon, Christchurch City and Anzac stations were sent to the scene from about 11.17am.
A Waka Kotahi NZTA Canterbury spokesperson said State Highway 76 was closed on Monday between Port Hills Rd and Chapmans Rd due to a fire. Police were managing traffic in the area.
Traffic congestion continued to affect the area this afternoon and motorists were urged to avoid the Port Hills Rd and Hillsborough areas if possible.
Residents in the area are also urged to keep their windows and doors closed until the fire is under control and the smoke has stopped.
FENZ said several crews from across the area were at the scene. Helicopters were also being used to fight the blaze.