Ronnie Sandahl is a Swedish filmmaker, author and screenwriter. He is best known for directing the coming of age Swedish drama film Underdog (2014), which won the Gold Hugo Award at the Chicago International Film Festival and the Critics Choice Award at the Zurich Film Festival that year. In 2017, Sandahl penned the screenplay for the acclaimed biographical sports drama Borg vs McEnroe, which had Shia LaBeouf and Sverrir Gudnason in lead roles and opened to positive reviews.