The Los Angeles Times said her grandson, Jonathan Weedman, confirmed that she died Monday in her Hancock Park home after a lengthy illness.
Weedman said Knight was born to be first lady, saying she was a genuine, effusive person whom people adored.
Virginia Knight was an early proponent of turning the Victorian governor's mansion, which was built in 1877 in Sacramento, into a museum honoring California's first ladies.
After her husband lost the 1958 governors race to Edmund G. "Pat" Brown, the couple returned to Los Angeles. Goodwin Knight died in 1970.