Yes. Backswimmers are aquatic true bugs: insects in the order Hemiptera (family Notonectidae). They are slender water insects that usually swim belly-up with long, oarlike hind legs, and they use piercing-sucking mouthparts to prey on other small aquatic animals.
That places them with other “true bugs,” not with beetles or flies. The Missouri Department of Conservation field guide lists backswimmers as Notonectidae in the order Hemiptera (true bugs).