Polyolefin blend compositions

The present disclosure relates to polypropylene-based and polyethylene-based polyolefin compositions having improved impact properties. In at least one embodiment, a polyolefin composition includes an ethylene polymer, a propylene polymer, a propylene-based elastomer, and an ethylene-based plastomer. Compositions of the present disclosure can have one or more of: a Notched Charpy impact strength at 23° C. of 8 kJ/m2 or greater, a Notched Izod Impact Strength at 23° C. of 6 ft-lb/in. or greater, an Unnotched Izod impact strength at 23° C. of 10 ft-lb/in. or greater, and a portion of the composition having a submicron domain content of 50% or greater per mm2.