Good news: yes, in most cases you can buy just the replacement seat for an urban bench separately. Many manufacturers and street furniture suppliers sell seat panels, slat sets, or bench top kits as individual replacement parts, so you usually do not have to replace the whole bench.
The key is matching the replacement seat to your bench. Start by checking the underside of the bench or any original paperwork for a brand name and model number. If that is not available, measure the existing seat carefully: overall length, width, thickness, and the spacing between mounting holes. Also note the material—wood, recycled plastic, powder-coated steel, aluminum, or expanded metal—because different materials use different mounting hardware and spacing.
Once you have those details, you can order from the original manufacturer, an authorized dealer, or a supplier that specializes in commercial outdoor furniture parts. Some brands sell replacement seats directly online, while others can give you a quote if you contact them with the model number and photos.
If the original seat has been discontinued, do not worry. Universal replacement slats, replacement wood kits, and custom-cut seat panels are widely available for many urban bench frames. Just confirm that the replacement is rated for outdoor use and that the mounting holes line up with your frame. When in doubt, send the supplier a few clear photos and measurements. A decent parts supplier will confirm compatibility before you buy.
So yes—buying just the replacement seat is usually possible, and it is often the most affordable way to bring a worn urban bench back to life.