IGY may refer to:
- Immunoglobulin Y, a type of antibody found in birds but not mammals
- International Geophysical Year
- "I.G.Y. (What a Beautiful World)", a 1982 song by Donald Fagen
- Israel Gay Youth
disambiguation page lists articles associated with the title IGY.
If an internal link led you here, you may wish to change the link to point directly to the intended article.