Highly stretchable and self-healing polymer gels formed solely by physical entanglements of ultrahigh-molecular weight (UHMW) polymers were fabricated through a facile one-step process. Radical polymerization of vinyl monomers in ionic liquids under very low initiator concentration conditions produced UHMW polymers of more than 106 g/mol with nearly 100% yield, resulting in the formation of physically entangled transparent polymer gels. The UHMW gels showed excellent properties, such as high stretchability, high ionic conductivity, and recyclability. Furthermore, the UHMW gel exhibited room temperature self-healing ability without any external stimuli. The tensile experiments and molecular dynamics simulations indicate that the nonequilibrium state of the fractured surfaces and microscopic interactions between the polymer chains and solvents play a vital role in the self-healing ability. This study provides a physical approach for fabricating stretchable and self-healing polymer gels based on UHMW polymers.