DY, D. Y., Dy, or dy may refer to:
In science and technology, and mathematics
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
Other sciences
- dy, in calculus, Leibniz's notation for the differential of a variable y
- Dysprosium (symbol Dy), the 66th chemical element
- 1,4-Dioxane, a common solvent
Businesses
- Norwegian Air Shuttle (IATA code DY)
- Alyemda, a Yemeni airline (IATA code DY, until 1993)
- 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 postcode area in Britain
- DY Patil Stadium, a cricket stadium in India
- D. Y. Patil college of Engineering and Technology, Kolhapur in India
- Dee Why, New South Wales, a suburb of Northern Sydney, Australia
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
- Die (disambiguation)
- Dye (disambiguation)
- YD (disambiguation)