Great question—and the answer really depends on where the bench is being used. For most public park benches, the short answer is no: they do not come with optional cushions, and the seats are designed to be weather-resistant, easy to clean, and tough enough to handle heavy use. Adding cushions to public benches would create maintenance and storage headaches, so cities and park departments typically skip them entirely.
When you move into residential outdoor furniture, however, the answer changes. Many garden benches, patio benches, and porch benches are sold as the bench frame only. The cushion is often listed as an optional accessory or sold separately, especially for wooden or metal benches. Some higher-end patio bench sets do include matching cushions in the box, but you should always check the product listing for phrases like “cushion included,” “cushion sold separately,” or “optional cushion available.” If you already own a park bench or garden bench and want more comfort, you can buy universal outdoor bench cushions in standard sizes. Look for weather-resistant fabric, quick-dry foam, UV protection, and ties or non-slip backing so the cushion stays put. A 48-inch bench cushion or a 60-inch bench cushion tends to fit many common bench sizes, but measure first.
So, do park benches come with optional cushions? In public settings, almost never. For home use, some do, but many do not. My advice is to assume the cushion is sold separately unless the product description clearly says otherwise. If comfort is a priority, plan for a separate bench cushion purchase—or choose a bench-and-cushion set from a retailer that includes both.