Yes, by drilling access holes and filling the cavities, then patching. Dense-pack cellulose and injection foam are the two common methods. Spray foam as such needs an open cavity, so it is not the product for closed walls.
More detail
Walls in the mix of pre-war stock in the older Columbus neighborhoods, mid-century ranches in the inner suburbs, and large 1990s-onward subdivisions in the outer counties are frequently empty or filled with settled material that has lost most of its value, and gutting drywall to fix that is rarely justified on its own. The retrofit methods work through small holes instead. Dense-pack cellulose is the established approach. Holes are drilled in each stud bay, typically from the exterior siding side where the patch is invisible, and treated cellulose is blown in at high density until the bay resists further fill. The density is what matters: packed correctly it substantially reduces air movement within the cavity as well as adding R-value. It is the lower-cost option and it is proven. Injection foam is a slow-rise pour foam formulated for closed cavities, delivered through the same kind of access holes. It expands gently to fill irregular spaces and cures in place. It costs more than cellulose and is a genuine option where cellulose settling is a concern. What you cannot do is spray foam a closed wall. Spray foam is applied to an open surface and expands rapidly; there is no way to control it inside a finished cavity. A contractor proposing to spray foam your existing closed walls is describing injection foam or is confused about the product. Assessment before spending. A small inspection hole, or removing an outlet cover on an exterior wall, shows what is in there. An infrared scan on a cold day shows which bays are empty and which are filled, which is useful because partial fill is common. One caution specific to older houses: walls with knob-and-tube wiring still in service should not be filled until the wiring is replaced, and any existing moisture path into the wall needs solving first.