In this study, the combination of organomodified montmorillonite (MMT), magnesium hydroxide (MDH), graphene oxide (GO) and expandable graphite (EG) as intumescent flame retardant for Linear Low-Density Polyethylene-Cyclo-Olefin Copolymer (LLDPE/COC) blends has been investigated. An amine-alcohol modified polyethylene (PEgDMAE) was used as compatibilizer. Limiting oxygen index (LOI), cone calorimeter determinations and flammability test (Underwriters Laboratory - UL-94) were used to evaluate the flame retardant properties. The structural characterization was measured by FTIR and scanning electron microscopy (SEM). The mechanical properties were also evaluated by Dynamic-mechanical analysis (DMA). The PEgDMAE compatibilizer enhanced the filler dispersion and increased the LOI to 22% for clay, 23% for GO and 26.5% for EG composites. The results indicated that the combination of each additive makes it possible to reduce the total Magnesium hydroxide filler content from 55 to 20% to achieve the flame retardant requirements. The flame retardant and mechanical properties of LLDPE/COC blends increased to a higher extent when using the combination of these additive fillers.