The present study seeks to utilize the biochar prepared from red algae (AR) and its composite with iron oxide (Fe3O4)-nanoparticle (MBC-AR) to estimate their batch extent potential decontamination mechanism for fluoride ion removal from aqueous solution. Various characterization techniques have been analyzed to study the functional groups, including F -IR, XRD, EDS, SEM, FE-SEM, TEM and VSM of the synthesized adsorbent (MBC-AR). Several adequate batch adsorption studies were performed to ascertain the equilibrium state. The research yielded a well-established langmuir adsorption isotherm with a capacity for adsorption of 96.4 mg/g, and it suited well to a pseudo-second-order kinetic model. According to reports, the MBC-AR is a useful bio-adsorbent for eliminating fluoride ions from wastewater and other large-scale uses. At room temperature (298 K), the effects of bio-adsorbent doses (10-150 mg), initial concentration of adsorbate taken (20-80 mg/L), pH value (2.0-10.0), as well as contact time (0-250 min) were assessed for fluoride removal using MBC-AR. The efficacy of adsorption and its statistical data were well-established with a pseudo-second-order mechanism and Langmuir isotherm (R-2 = 0.99). It was determined that the highest adsorption efficacy and capacity were 96.4 mg/g in the phase equilibrium process.