The thermoelectric and thermodynamic characteristics of CdYF3 were examined for the first time using the density functional theory (DFT) framework within the generalized gradient approximation (GGA). The stability of the material is justified by calculating the optimization and phonon calculation. We employed diverse approximations like LDA, WC- GGA, PBE-GGA, and GGA-PBE-sol approximation to analyse the variation in the band gap while these approximations reveal an underestimate of the bandgap. Therefore we, employed the GGA+Trans-Blaha modified Becke–Johnson (TB-mBJ) approach to get the accurate bandgap with 2.305 eV value from (M-X) of the CdYF3 compound. Additionally, we computed transport properties against the temperature, Chemical potential, and charge carrier concentrations of the CdYF3 compound. At the optimum charge carriers, the calculated power factor suggests that p-type CdYF3 has a power factor. We also calculated the thermodynamics properties to evaluate the heat capacity at constant volume and pressure, enthalpy, etc. As a result, significant ZT in CdYF3 was achieved at higher values at room temperature to use in the thermal devices