The biomemristor has gained considerable attention because of its exceptional scalability, remarkable flexibility, simplicity of processing, and low manufacturing cost. Natural biomaterial-based memristors have been demonstrated for prospective application due to their sustainability, non-toxicity, environmental friendliness, degradability, and biocompatibility. Hence, the leaf extract of the traditional medicinal tree neem ( Azadirachta indica ) was employed in this study to efficiently synthesize a biomaterials-inspired thin film for biomemristor applications. Various morphological, compositional, structural, surface functional, optical, and thermogravimetric analyses were performed on neem thin film. Satisfactory bipolar, reversible and repeatable resistive switching characteristics were obtained. Furthermore, phototunable resistive switching behaviours were examined by embedding carbon quantum dots (CQDs) with neem to develop a CQDs@neem composite biomemristor, which resulted in a 16% reduction in SET voltage and a 2.6% rise in RESET voltage. Satisfactory memristive behaviour was achieved, including appropriate endurance, retention, and a stable resistance ratio between high and low resistance states. The underlying current conduction mechanisms were explored. Finally, a method involving the formation/annihilation of an Ag metal filament and an ionized molecular vacancy filament is proposed to explain the resistive switching behaviour of CQDs@neem composite memristors.