Fructose dehydration yields 5-hydroxymethylfurfural (5-HMF), a multifaceted precursor for clean fuels, advanced biofuels, and fuel additives. In this work, we developed a magnetic solid acid (BMSA) derived from rice husk as a proficient catalyst in the production of 5-HMF. This study investigated the influence of calcination conditions on the acid content of the catalyst, with the objective of enhancing its performance. The study factors include the effects of temperature, solvent, reaction duration, and catalyst mass, which were investigated. 5-HMF was synthesized with a yield of 72% in 3 h using 2 mg of catalyst in DMSO at 120 °C. Interestingly, the catalyst exhibited facile recovery with an external magnet and demonstrated efficient reusability for up to four cycles.