Abstract In this study, we contribute the facile fabrication of tough polyolefin monoliths from their polymer solutions using a phase separation method. Compressive stress–strain tests demonstrate that the monoliths have excellent mechanical properties. The monoliths show macroporous structures where the pore sizes can be tuned from sub-1 to 16 µm by adjusting the fabrication conditions. The monoliths exhibit high hydrophobicity/ oleophilicity and good resistance toward different chemicals. Based on the above properties, we applied the monoliths to the selective absorption of oil from an oil/water mixture. By simply squeezing the monoliths, the absorbed oil can be recovered. The monoliths are useful for more than 10 cycles of absorption and recovery, showing a good stability for industrial-scale oil spill treatment.