The present study effectively utilizes the Crassostrea angulata (oyster) marine waste shell to prepare biocompatible titanium (Ti) doped hydroxyapatite (Ti/HAp) through the most popular and widely researched precipitation technique. The prepared Ti/HAp sample was extensively characterized by FTIR, XRD, FE-SEM, EDX mapping, HR-TEM, together with SAED patterns. The extremely intense peak in XRD diffractograms and the absorption peaks in FTIR (groups such as PO<inf>4</inf>^3â, OH^â, and CO<inf>3</inf>^2â) confirm the formation of crystalline hexagonal-shaped hydroxyapatite (35 nm) in the Ti/HAp matrix. The micrographs of FE-SEM and HR-TEM images at different magnifications portray the distinct rod-like structure of synthesized Ti/HAp. In addition to XRD results, the SAED pattern shows the crystalline nature of the synthesized Ti/HAp. The antibacterial properties and cell viability of the synthesized Ti/HAp composite were thoroughly investigated. The antibacterial activity of Ti/HAp was rigorously evaluated against two distinct bacterial strains: the gram-negative Escherichia coli and the gram-positive Staphylococcus saprophyticus. The cytocompatibility of Ti/HAp was thoroughly evaluated through an MTT assay, utilizing osteoblast cells, specifically the MG-63 cell line. The role of Ti in the antibacterial and cell viability activity of the product was assessed through suitable mechanisms. The cell viability decreases as Ti/HAp concentrations increase. It exhibits cell viability of 80 at the low concentration of 7.8 µg/mL. In both bacterial strains, Ti/HAp demonstrated good antibacterial activity at increasing doses. Consequently, the prepared Ti/HAp demonstrates excellent antibacterial activity and cell viability, making it suitable for various biomedical applications. © 2025 Elsevier B.V., All rights reserved.