Lys

Lys may refer to any of the following:

;Places
*The Lys River or Leie, a river in France and Belgium
*Lys (torrente), a stream of Aosta Valley in Italy
*Lys, Pyrénées-Atlantiques, a commune in the Pyrénées-Atlantiques department in France
*Lys (département), a "département" during the First French Empire, nowadays in Belgium
*Lys, an old orthography of Liss, Hampshire, England
*LYS can also refer to a Local Yarn Shop for knitters or crocheters

;Aviation
*"LYS", the IATA Airport Code for Saint-Exupéry International Airport near Lyon, France

;Battles
*Battle of the Lys, a World War I battle in the spring of 1918

;Fiction
* Lys is the name of a city in Arthur C. Clarke's book The City and the Stars.
* Lys is also the name of a city in George R. R. Martin's epic series A Song of Ice and Fire.

;Heraldry
*Fleur-de-lys or Fleur-de-lis, a stylized representation of a lily or iris, used in heraldry

;Science
*"Lys" is an abbreviation for the amino acid lysine

;People
*Jan Lys (c1590-1629), a German painter