Graphene-based composites have shown great potential to improve properties at the lab scale. However, for industrial applications such as flexible packaging, the number of examples that demonstrates improved properties by such composites is limited. Thus, in this work, a high-density polyethylene (HDPE), a common packaging material and industrial grade graphene (G) were used to prepare composites for flexible packaging applications. The composite flexible films of around 100 μm thick with a multilayer structure were produced by coextrusion cast film, an industrial compatible technique. The prepared films were investigated by means of oxygen and moisture barrier properties, tensile response, electrical conductivity and light transmittance. At a maximum loading of 1 wt.% G successfully reduced the permeability in 41% and 44% for moisture and oxygen, respectively. Although at this concentration, little effect was observed in the tensile properties and the electrical conductivity remained the same. Based on the obtained results G shows as a feasible way to produce industrial scale flexible multilayer films composites at loadings below 1 wt.% with improved barrier properties. Higher G content leads to the filler agglomeration negatively affecting the composites’ barrier properties, which it can be addressed by layers design.