In the title salt, C18H15ClNO+· HSO4 -, the quinolinium ring system is approximately planar, with a maximum deviation of 0.028 (2) Å, and forms a dihedral angle of 78.43 (4)° with the attached phenyl ring. A pair of inter-molecular O - H⋯O hydrogen bonds links two hydrogen sulfate anions into a dimer, generating a R 2 2(8) ring motif. Inter-molecular N - H⋯O hydrogen bonds and C - H⋯O contacts link the ions into a three-dimensional network. The structure is further stabilized by C - H⋯π inter-actions.