Novel quinternary Cu2Cd1 − xMnxSnS4 (0 ≤ x ≤ 1) semiconductor thin films were deposited onto glass substrates at 300 ℃ by the spray pyrolysis technique to study the effect of Mn content on the structural, compositional, topographical, optical, and electrical properties. X-ray diffraction analysis showed that an increase in Mn content in the Cu2Cd1−xMnxSnS4 films resulted in a transition from the cernyite to stannite phase tetragonal crystal structure and a change in lattice parameters. The intensity of the predominant 112 peak was observed to be relatively low at higher Mn content. Energy dispersive X-ray analysis revealed that the Cu2Cd1 − xMnxSnS4 films were Cu-poor, Sn-poor and close to stoichiometry. Atomic force microscopy revealed that the average roughness of the films fluctuated between 43.9 -73.95 nm. Optical characterization showed a high absorption coefficient of 105 cm−1 while the direct optical band gap and Urbach energy varied between 1.79–1.92 eV and 226–564 meV, respectively with an increase in Mn content. Electrical resistivity, hole mobility and carrier concentration were observed to fluctuate between 8.5 x102- 2.4 x 101 Ωcm, 1.31 x 101- 6.24 x103 cm2V/s and 2.0 x 107-5.03 x1013 cm−3, respectively with an increase in Mn content. The Cu2Cd1−xMnxSnS4 films exhibited a p-type conductivity.