In enzymology, a formimidoylglutamate deiminase () is an enzyme that catalyzes the chemical reaction
Thus, the two substrates of this enzyme are N-formimidoyl-L-glutamate and H<sub>2</sub>O, whereas its two products are N-formyl-L-glutamate and NH<sub>3</sub>.
This enzyme belongs to the family of hydrolases, those acting on carbon-nitrogen bonds other than peptide bonds, specifically in linear amidines. The systematic name of this enzyme class is N-formimidoyl-L-glutamate iminohydrolase. Other names in common use include formiminoglutamate deiminase, and formiminoglutamic iminohydrolase. This enzyme participates in histidine metabolism.