In the cation of the title salt, C17H23N2O+·Br−, the adamantyl moiety and the pyridiniminium ring are inclined to the ketone bridge by torsion angles of −78.1 (2) (C—C—C=O) and 58.3 (2)° (C—C—N—C), respectively, and the ketone bridge has a C—C—C—N torsion angle of 174.80 (15)°. In the crystal, the cations are connected into chains parallel to the c axis by C—H...O hydrogen bonds. The chains are further linked into layers parallel to the bc plane by N—H...Br and C—H...Br hydrogen bonds, C—H...π interactions and π–π stacking interactions [centroid-to-centroid distance = 3.5657 (11) Å]. A Hirshfeld surface analysis, which comprises the dnorm surface, electrostatic potential map and two-dimensional fingerprint plots, was carried out to verify the contribution of the various intermolecular interactions.