A man has been charged over the death of a cyclist who was hit and killed at Pymble in Sydney's north on December 18.

Police say the man's car hit 33-year-old doctor Ann Formaz-Preston near the intersection of Woodlands Avenue and Mona Vale Road as she was riding on Mona Vale Road with a group of friends.

Despite the efforts of paramedics and bystanders, the Canadian expat died at the scene.

The 37-year-old driver of a Toyota Corolla sedan was arrested at the scene and returned negative alcohol and drug tests.