A novel magnetic monolithic catalyst based on K2CO3/γ-Al2O3/Sepiolite/γ-Fe2O3 was developed seeking to convert efficiently soybean oil and bioethanol to ethanolic biodiesel and glycerol. The magnetic monolithic was attained by extrusion method and characterized by EPR, VSM, SEM, Dynamometry, XRD, BET, and CO2-TPD, showing satisfactory magnetic, morphological, mechanical, structural and textural properties. The catalytic performance of this monolithic catalyst was also evaluated in a reactor assisted by magnetic field. The reactor was operated in a closed loop, recycling the reaction mixture. High oil conversion to biodiesel was obtained using 5 wt% of catalyst with 1:12 oil/ethanol molar ratio at 70 °C after 1.5 h. The magnetic properties of this monolithic catalyst allowed the bed stabilization under magnetic field and the catalysts separation, enabling its reuse by four reaction cycles. The authors are grateful to the State University of Northern of Rio de Janeiro for the Postdoctoral Position Fellow (No. 001/2017), Institutional Program of the Estacio de Sá University for Research Productivity Fellow and the Brazilian agencies: FAPERJ (E-26/210.508/2014) and CAPES (Finance Code 001) for the financial support.