The two-vehicle crash on Depot Rd, View Hill, between Harmans Gorge Rd and Watsons Reserve Rd, in the Waimakariri district was reported to police about 1.50pm.
A police spokesperson said one person has died following the serious crash and another person has reportedly sustained serious injuries.
"The road will remain closed while the Serious Crash Unit examines the scene.
"Motorists should avoid the area, if possible."
Diversions are now in place and the Waimakariri Gorge Bridge remains open.