In enzymology, a ricinine nitrilase () is an enzyme that catalyzes the chemical reaction
Thus, the two substrates of this enzyme are ricinine and H<sub>2</sub>O, whereas its two products are 3-carboxy-4-methoxy-N-methyl-2-pyridone 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 nitriles. The systematic name of this enzyme class is ricinine aminohydrolase. This enzyme participates in nitrogen metabolism.