"Crazy" is a song written by English singer-songwriter Seal and English songwriter Guy Sigsworth. It was produced by Trevor Horn and released by ZTT Records in November 1990 on Seal's debut album, Seal (1991). The song became his first commercial hit, reaching No. 2 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.

Seal Henry Olusegun Olumide Adeola Samuel is a British musician, singer, songwriter, and record producer. He has sold over 20 million records worldwide. These include hit songs "Crazy" and "Killer", the latter of which went to number one in the UK, and his most celebrated song, "Kiss from a Rose", which was released in 1994.