Disodium guanylate, also known as sodium 5'-guanylate and disodium 5'-guanylate, is a natural sodium salt of the flavor enhancing nucleotide guanosine monophosphate (GMP). Disodium guanylate is a food additive with the E number E627. It is commonly used in conjunction with glutamic acid.

As it is a fairly expensive additive, it is usually not used independently of glutamic acid; if disodium guanylate is present in a list of ingredients but MSG does not appear to be, it is likely that glutamic acid is provided as part of another ingredient such as a processed soy protein complex. It is often added to foods in conjunction with disodium inosinate; the combination is known as disodium 5'-ribonucleotides.

Disodium guanylate is produced by fermentation. It is often added to instant noodles, potato chips and other snacks, savory rice, tinned vegetables, cured meats, and packaged soup.