In short, sometimes they do—but not always. It really depends on the type of urban outdoor furniture and where it is going to be used. Many commercial-grade chairs designed for public spaces, such as city plazas, campuses, transit stops, parks, and business districts, are available with anti-theft locking features. These features are usually built in or offered as add-ons rather than being standard on every chair.
Common anti-theft options include tamper-resistant bolts, concealed locking plates, ground anchors, chain or cable locking points, removable seats with locking mechanisms, and integrated locks that secure the chair to a fixed base. Some manufacturers also design public seating security systems so that individual chairs can be locked together or anchored to the pavement. The goal is to make opportunistic theft difficult without making maintenance impossible.
That said, not all urban outdoor furniture comes with anti-theft chair locking. Decorative or residential-style outdoor chairs may have no locking features at all. If you are buying for a public or high-traffic area, it is worth asking the supplier directly about locking features, anchor kits, key management, replacement parts, and warranty coverage. Also keep in mind that locking features work best as part of a broader public seating security plan—good placement, anchoring, and site supervision still matter. So if theft is a concern, specify anti-theft locking features for chairs before you order rather than assuming they are included.