She was Sandra Loveday, aged 60.
Emergency services were called to the crash in Old West Coast Rd, West Melton, at 11.15pm on Monday.
A witness to the crash said the state highway running through the Selwyn District was wet when emergency services arrived, as it had just begun to rain.
Two cars were in crumpled heaps on each side of the straight stretch of road.
Rural area commander Pete Cooper earlier said one person was in each car when they collided.
Police have been unable to speak with the teen as he’s yet to wake up in Christchurch Hospital's intensive care unit.
Loveday was a senior legal executive at Canterbury Legal. The company announced her death on its website.
“Sandra’s presence within our small team was invaluable, and her professionalism and warmth left a lasting impact on all who had the privilege of working alongside her. Her loss has left us deeply shocked and saddened, and we are navigating this together.
“Our thoughts are with Sandra’s family and friends at this difficult time.”
The police Serious Crash Unit was trying to determine why one car was on the wrong side of the road.
“The road is reasonably straight so we wouldn’t call it a high-risk road,” Cooper told The New Zealand Herald.
“Every road is difficult to navigate if you’re concentrating on something else, at this stage we can’t rule out the road as a factor but it’s not a difficult stretch of road.”
