DY, D. Y., Dy, or dy may refer to:
Science and technology , Leibniz's notation for the differential of a variable y Dysprosium (symbol Dy), a chemical element 1,4-Dioxane, a solvent
Astronomy DY Persei, a variable star in the Perseus constellation DY Persei variable, a subclass of R Coronae Borealis variables DY Eridani, a triple star system less than 16.5 light years away from Earth
Businesses Norwegian Air Shuttle (IATA code: DY) Alyemda (former IATA code: DY), a former Yemeni airline DY, clothing brand of singer Daddy Yankee
People Dy (surname), a surname in various cultures (including a list of people with the surname) DY (rapper) (born 1984), Canadian rapper DY, member of the American record production and songwriting team 808 Mafia Lady Di, Diana, Princess of Wales
Places DY, the official International vehicle registration code for Benin (formerly Dahomey) DY postcode area, in England DY Patil Stadium, a cricket stadium in India D. Y. Patil college of Engineering and Technology, Kolhapur, in India
Other uses dy (digraph), a digraph used in rendering the Xhosa and Shona languages, as well as some Australian Aboriginal languages such as Warlpiri Deputy (disambiguation) DY, a line of clothing from Puerto Rican singer Daddy Yankee
See also Dee Why, a suburb in Sydney, Australia Die (disambiguation) Dye (disambiguation) YD (disambiguation)