<p>This work focuses on the synthesis of four novel lanthanide complexes: La (III), Ce (III), Nd (III), and Dy (III) with carbamazepine (CBZ). The geometric structural and bonding mode of synthesized complexes were accomplished by various analytical and spectroscopic techniques and the data reveal that the novel complexes have a 1:2 (Ln³⁺:CBZ) electrolytes with general formula [Ln(CBZ)₂(H₂O)Cl]Cl₂.H₂O and molecular weight: 753.83, 791.07, 777.19 and 777.43 for Ln³⁺ complexes respectively. The spectral studies investigated that CBZ interacts as a bidentate ligand via the amide group’s nitrogen and oxygen atoms in its moiety, and the geometric octahedral structure was confirmed by density function theory. On the other hand, PXRD data provided that the ligand and its complexes have nature that is crystalline. Antimicrobial activity was tested for their effectiveness against various Gram-positive and negative bacteria and anti-fungal efficacy, in addition to the efficiency of their cytotoxicity against cancer cell lines such as (Hep-G2 and MCF-7) to assess their potential as chemotherapy agents where the IC₅₀ for Ln³⁺ complexes in the range (0.095–0.242) and (0.110–0.298) µM against Hep-G2 and MCF-7 cancer cell lines, respectively and La(III) demonstrated a high degree of activity, similarly, in the case of antimicrobials, it showed the highest activity. The ability of these complexes to bind to the active sites of the Bacillus subtilis receptor (PDB ID: 6A4M) and methionine adenosyl-transferases in liver tumors (PDB ID: 5A19) and human breast cancer MCF-7 (PDB ID: 4zvm) was evaluated using molecular docking studies utilizing MOA2022 software. According to the following pattern, the binding strength increased as the binding energy decreased: CBZ˂[Dy(CBZ<b>)</b>₂(H₂O)Cl]²⁺˂[Ce(CBZ<b>)</b>₂(H₂O)Cl]²⁺˂ [Nd(CBZ<b>)</b>₂(H₂O)Cl]²⁺˂[La(CBZ<b>)</b>₂(H₂O)Cl]²⁺, indicating that the highest binding affinity and possible biological activity were displayed by the La(III) complex.</p>