In the title compound, C17H16ClN5O3, the phenyl and the oxadiazole rings are almost coplanar, subtending a dihedral angle of 4.34 (19)°. These rings lie almost normal to the pyridazine ring, making dihedral angles of 87.35 (16) and 89.06 (15)°, respectively. The morpholine ring has the usual chair conformation and its mean plane is inclined to the pyridazine ring by 39.45 (17)°. There is a short intramolecular C—H...Cl contact present. In the crystal, molecules are linked by bifurcated C—(H,H)...O hydrogen bonds and a C—H...N hydrogen bond, forming layers parallel to theabplane.