Palmitoleic acid (IUPAC name Hexadecenoic acid) is a Ω-7 monounsaturated fatty acid with the molecular formula C₁₆H₃₀O₂.

It is a common constituent of the glycerides of human adipose tissue (fat) and present in all tissues, but generally found in higher concentrations in the liver. It is biosynthesized from palmitic acid by the action of the enzyme Δ-9 desaturase.

Dietary sources of palmitoleic acid include a variety of marine oils, vegetable oils, and animal oils. Macadamia oil and Sea Buckthorn oil are botanical sources with high concentrations, containing 22% and 40% of palmitoleic acid, respectively.

In a recent study examining the effects of diets high in various fatty acids, total cholesterol and low density lipoprotein (LDL, "bad cholesterol") concentrations were similar with palmitoleic and palmitic acids and significantly higher than with oleic acid. High density lipoprotein (HDL, "good cholesterol") was significantly lower with palmitoleic than with palmitic acid. The study confirms that, at least in hypercholesterolemic men, a modest increase in palmitic acid raises LDL cholesterol relative to oleic acid, even when dietary cholesterol is low. Palmitoleic acid behaves like a saturated and not a monounsaturated fatty acid in its effect on LDL cholesterol.