The transportation sector causes more than half of California's carbon pollution, and parts of the state are vexed by some of the most toxic air in the country, according to the governor's office.
"For too many decades, we have allowed cars to pollute the air that our children and families breathe," Newsom said in a release.
"Our cars shouldn't make wildfires worse -- and create more days filled with smoky air. Cars shouldn't melt glaciers or raise sea levels threatening our cherished beaches and coastlines."
The order was described as an aggressive effort to move the state further away from reliance on climate changing fossil fuels.
Regulations will be developed to mandate that all in-state sales of new passenger cars and trucks be zero-emission by the year 2035, and that all medium- and heavy-duty trucks be emission-free by 2045 "where feasible."
The order won't prevent California residents from owning gasoline-powered cars or selling used models, according to the governor's office.
It does call for partnerships with private businesses to speed up creation of charging networks for electric cars and stations for non-polluting fuels such as hydrogen.
California is a major car market, but devastating wildfires have become frequent occurrences as climate change leaves trees and brush tinder-dry.
Infernos across California, Oregon and Washington states have burned more than five million acres (two million hectares) this year, killed dozens of people and forced hundreds of thousands from their homes.
California-based Tesla on Tuesday said it is slashing battery costs to speed a global shift to renewable energy, and could have a $25,000 self-driving model available in three years or so.