Illegal, or unlawful, is used to describe something that is prohibited or not authorized by law.

Illegal is a 2010 Belgian drama film directed by Olivier Masset-Depasse. The film was selected as the Belgian entry for the Best Foreign Language Film at the 83rd Academy Awards, but it did not make the final shortlist. The film received eight nominations at the 1st Magritte Awards, and won the awards for Best Actress, Best Supporting Actress and Most Promising Actress. The film is critical of practices of Belgian immigration officers.