Honestly, the short answer is no. A standard park bench warranty rarely covers vandalism or graffiti, and there is a simple reason for that: those are deliberate acts, not manufacturing defects. Most manufacturers stand behind their workmanship and materials, such as welds, frames, slats, and structural integrity, but they do not insure your bench against someone spraying it with paint or scratching it with a key.
That said, there are a few important details to understand before you buy.
First, read the warranty language carefully. A typical commercial park bench warranty might cover the powder-coated finish against peeling, cracking, or corrosion for a certain number of years. That does not mean it covers graffiti. In fact, if the removal method damages the finish, the original finish warranty may become void. Ask the supplier how graffiti should be removed without voiding the warranty.
Second, some manufacturers offer optional anti-graffiti coating systems. These are not a warranty against vandalism in the usual sense, but some coating brands come with a limited performance guarantee. For example, a sacrificial anti-graffiti coating may be warranted to allow graffiti removal without harming the underlying surface. That is useful, but it is a product warranty on the coating, not a promise that nobody will tag your bench.
Third, if you are buying for a municipality, school, or park district, you may have better luck bundling protection into a maintenance contract rather than relying on a bench warranty. Some suppliers or third-party service providers will clean, repair, and remove graffiti for a monthly or annual fee. That arrangement can act like a practical warranty against vandalism, but it is really a service agreement.
So, do park benches come with warranties against vandalism or graffiti? In most cases, no. What you can get is a solid structural warranty, an optional anti-graffiti coating, and a maintenance plan that handles cleanup quickly. If vandalism resistance is a top priority for your outdoor furniture, choose a park bench with a smooth, non-porous surface and ask about coating-backed graffiti removal systems before you buy.