"Crazy" is a song written by the English singer Seal and British songwriter Guy Sigsworth. It was produced by Trevor Horn for Seal's debut album, Seal (1991) and became his first commercial hit. It reached the top five in the United Kingdom, while becoming his first top ten single in the United States. It has since been covered by several artists, including Alanis Morissette, whose version was released as a single from her 2005 compilation album, The Collection.