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