The aim of this study was to produce crosslinked low-density polyethylene (LDPE) composites using peroxide and octavinyl polyhedral oligomeric silsesquioxane (OvPOSS) and to examine the shape memory behavior. The strategy was to use OvPOSS as a coagent to increase the crosslinking density and crosslinking efficiency while improving the mechanical and shape memory properties as well. The peroxide concentration, from 0.5 phr to 3.0 phr, was taken as the experimental parameter, with 4 phr OvPOSS added to all composites. The melt mixing route was applied similar to that which would be used industrially. The thermo-responsive shape memory properties near the melting point were examined in tension mode. The dispersion of OvPOSS in the LDPE matrix was observed via scanning electron microscopy and Si-mapping. In addition, the thermal, mechanical, structural, and rheological features of the novel LDPE/OvPOSS and LDPE/peroxide/OvPOSS systems were investigated. It was observed that the crosslinking density of LDPE increased in the presence of OvPOSS, which affected the mechanical, rheological and thermal properties and increased the shape recovery ratio of the LDPE.