3. Charlize Theron
Most actresses who are still single by the age of 40 were married before. Not Charlize Theron. She is legitimately single. However, she has been in some relationships.
Back in 1995, she was dating Craig Bierko for two years. After breaking up with him, she moved on to Stephan Jenkins for another two years relationship.
Then came her longest relationship ever with Stuart Townsend. They were together for about nine years. The couple shared two movies together, Trapped and Head in the Clouds.
After Stuart, there had only been rumors about her dating Keanu Reeves, Jeremy Renner, and Ryan Reynolds. Only until 2013, she was seen to be with another man, Sean Penn. Unfortunately, the couple broke up last year.