In the current study, it is aimed to scrutinize the physical properties of LiBeX (X = Sb, Bi) compounds in detail. Density‐functional‐theory‐based WIEN2k and the Vienna Ab initio Simulation Package, employing the generalized gradient approximation of Perdew–Burke–Ernzerhof, Wu–Cohen, and Tran–Blaha‐modified Becke–Johnson (TB‐mBJ) exchange‐correlation schemes, are utilized to better validate the outcomes. The compounds exhibit energetic, lattice dynamic, and mechanical stability. Electronic structure calculations using the TB‐mBJ functional reveal indirect bandgaps of 1.007 eV for LiBeSb and 0.789 eV for LiBeBi compounds, respectively. The partial charge distribution in the highest occupied molecular orbital and the lowest unoccupied molecular orbital discloses maximum charge localization around the X site. The examination of the crystal orbital Hamilton population reveals the strongest BeX bonding interactions among the bonding pairs. The physio‐mechanical properties indicate brittle and mechanically anisotropic behavior of both compounds, with covalent bonding characteristics. The comparative analysis suggests that the TB‐mBJ potential is suitable for bandgap calculations due to its close alignment with experimental results. Additionally, the optimized results for these compounds indicate their potential for use in optoelectronic devices, such as visible to ultraviolet sensors and photovoltaics. The determined properties are consistent with previous theoretical findings.