Cyl

Cyl or CyL or CYL may refer to:


 * Cylindrospermopsin, a cyanotoxin produced by a variety of freshwater cyanobacteria
 * Spanish initialism for Castile and León, an autonomous community of Spain
 * an abbreviation used in eyeglass prescription

People with the surname

 * Agnieszka Cyl (born 1984), Polish athlete
 * Wawrzyniec Cyl (1900–1974), Polish footballer