Bullock was born to the late German-born opera singer Helga Meyer, and American voice teacher John Bullock. She started singing as a child in Germany, where she also studied ballet and performed small parts in her Mother's operas. Bullock attended Washington-Lee High School where she was a cheerleader and was voted "Most Likely to Brighten up Your Day" by her class.
Bullock is single and has no children. She is dating motorcycle builder and Monster Garage host Jesse James and has also dated Troy Aikman, Matthew McConaughey and Ryan Gosling. She was engaged to actor Tate Donovan.
In October 2004, she won a multi-million-dollar judgment in a lawsuit against Benny Daneshjou, the builder of her Lake Austin, Texas mansion, a home in which she has never lived, claiming it is uninhabitable. The builder denies any wrongdoing and is appealing the verdict.
Bullock publicly donated $1 million twice to the American Red Cross, first to its Liberty Disaster Relief Fund and again over four years later, in response to the 2004 Indian Ocean earthquake and tsunamis.