Liam Costner may not be as well-known as his famous father, Kevin Costner, but fans have been interested in his story for a long time. Liam is the son of Kevin Costner and Bridget Rooney, two famous people whose relationship made news in the mid-1990s. Liam is from of one of the most famous entertainment families, but he has decided to stay out of the spotlight in the movie business.