Yes, you can often order a single replacement leg for a park bench, but it depends on the bench style, brand, and how the leg is attached. A broken leg does not mean the whole bench is junk. In many cases, a replacement park bench leg is sold as a separate part, especially for metal frame benches and commercial site furniture.
Start by looking for a brand label or model number under the seat, on the frame, or near the center rail. If you find the manufacturer, contact their parts department or check the parts diagram on their website. Many brands sell individual legs or leg assemblies, so a park bench leg replacement may be easier than you expect.
If the original part is discontinued or the bench is unbranded, measure the leg height, mounting plate width, bolt hole spacing, material, and overall shape. Take photos of the unbroken leg and the damaged area. With those measurements, you can search park bench parts suppliers or outdoor furniture hardware retailers for a universal replacement leg.
For welded steel frames or unusual designs, a local metal fabrication shop can cut and weld a matching leg. If the bench has a decorative cast aluminum end frame, the repair may require an adapter plate or replacing the entire end frame instead of just one leg.
Whenever you repair park bench hardware, match the finish or coating for outdoor exposure, use galvanized or stainless bolts, and inspect the other legs. If the opposite leg is rusty or bent, replace both so the bench sits level and remains safe.
So the short answer is yes—one leg is often available. Just know your measurements, attachment style, and material before you order.