YD, or Yd may refer to:
Ydessa Hendeles, C.M., O.Ont., PhD, LL.D. (Hon.), D.F.A. (Hon.), A.O.C.A.D., D.T.A.T.I. (born 1948 in Germany) is a Canadian artist-curator and philanthropist.
Ydanis Rodríguez (born June 18, 1965) is the Council member for the 10th District of the New York City Council.
In molecular biology, the protein domain, Ydc2 (also known as SpCce1), is a Holliday junction resolvase from the fission yeast Schizosaccharomyces pombe that is involved in the maintenance of mitochondrial DNA.
The YdaO/YuaA leader (now called the cyclic di-AMP ribsowitch) is a conserved RNA structure found upstream of the ydaO and yuaA genes in Bacillus subtilis and related genes in other bacteria.
Ydin (meaning Nuclear in English) is a bi-monthly political magazine published in Helsinki, Finland.