Glyceraldehyde is a triose carbohydrate with the chemical formula C₃H₆O₃. It is the simplest of all aldoses. It is a sweet colorless crystalline solid that is an intermediate compound in carbohydrate metabolism. The word comes from combining glycerine and aldehyde, as glyceraldehyde is merely glycerine with one hydroxide changed to an aldehyde.

Glyceraldehyde has a chiral centre and therefore exists in D- and L- forms.

It may be prepared, along with dihydroxyacetone, by the mild oxidation of glycerol, for example with hydrogen peroxide and a ferrous salt as catalyst.