Silicate materials have the potential for application in the biomedical field. This research aims to investigate the effect of incorporating magnesium silicate into the hydroxyapatite (HA) matrix. Four batches of HA; which was synthesized from fish bones; and Mg silicate with various concentrations (5, 10, and 15 mass %) were prepared by solid-state method. The as-prepared Mg silicate/HA compositions were uniaxially dry-pressed and sintered at different temperatures. The effect of the Mg silicate doping on the physico-mechanical properties of Mg silicate/HA composites was investigated. Results showed that the phase composition of the sintered Mg silicate powder is formed of two phases; forsterite and clinoenstatite. Results for the Mg silicate/HA composite showed the complete disappearance of the HA phase, due to a reaction between Mg silicate and HA. This reaction led to the dissociation of forsterite into clinoenstatite with less Mg content and whitlockite rich in magnesia. Incorporation of Mg2+ with hydroxyapatite reduced the bulk density and increased the apparent porosity of the Mg silicate/HA samples. Increasing the Mg silicate content to 10 wt. % enhanced the mechanical properties, while addition of more than 10 wt. % Mg silicate reduced the bending strength and fracture toughness and boosted the Vickers hardness.