The laser thermal lens spectroscopy (TLS) was used to measure the thermo-optical parameters of alcohols(1)–trichloromethane(2) binary mixtures with high accuracy. Using this spectroscopic method, the thermal lens characteristic time (tc), thermal diffusivity (Dth), thermal conductivity (k), thermo-optic coefficient (dn/dT), and the refractive index changes with the sample deposited heat (dn/dQ) were measured for each of the pure components of this binary mixture at 298 K and fixed laser energy. The experimental results are in good agreement with the reference data. Then, for these binary mixtures, the dependency of k, dn/dT, and dn/dQ on the concentration was obtained and molecularly analyzed. The results show that increasing the volume fraction of alcohol in these binary mixtures leads to increasing k, dn/dT, and dn/dQ of these binary mixtures.