A huge quantity of synthetic toxic materials ends-up in water bodies causing long-lasting environmental and economic impacts due to catastrophic oil spill. Exploring marine algae as sorbent materials for oil spill remediation is a relatively new area and holds great potential. Herein, macroalgae Rhizoclonium hookeri (RH) derived magnetically recoverable RH-activated carbon (RHAC@Fe3O4) composite has been proposed as an innovative and robust strategy for oil spill clean-up. The application of RHAC@Fe3O4 composite was investigated for oil removal by varying time (10–60 min), dosage (0.2–1 g) and temperature (20, 30, 40 °C) to ascertain its optimal performance using both unused and used motor oil. Characterization studies showed that KOH activation resulted in developing pore structure and surface functionalities in the algal biochar. The percentage of oil uptake from simulated oil spill was over 90 % in 30 min at room temperature using 0.8 g composite. Moreover, Fe3O4 loading onto carbon material allowed magnetic separation as a convenient alternative to filtration for the recovery of oil laden composite. Apart from superior oil removal ability, synthesized composite demonstrated robust performance up to four cycles in synthetic sea water matrices. Comparative study revealed better oil sequestration efficiency of RHAC@Fe3O4 (93 %) as compared to its precursors, i.e. algal biochar (71 %) and AC (88 %). Based on these findings, it is advocated that designed RHAC@Fe3O4 composite being eco-friendly, economical and readily recoverable with enhanced oil uptake ability could potentially be an innovative platform for oil spill clean-up applications.