Short answer: usually yes, but not automatically. In an apartment building's shared courtyard, the furniture is sitting in a semi-public space, so you need to think about rules, weather, security, and neighbors before you treat it like your own patio.
Start with the building's rules. Your lease, HOA, co-op board, or strata bylaws may say whether personal furniture can stay in common areas. Some buildings allow a few chairs or a small table; others require everything to be moved after use. If the courtyard is a fire exit route, don't place furniture where it can block doors, paths, or emergency access. A quick email to management can save you a fine or a nasty note.
Then consider the furniture itself. Urban outdoor furniture needs to handle rain, sun, wind, and maybe pollution. Powder-coated metal, teak, HDPE, and weatherproof wicker are better than untreated wood or cheap fabric. Even outdoor furniture lasts longer with covers and periodic cleaning. In windy cities, lightweight chairs should be secured or stored, because flying furniture can damage windows or hurt someone.
Security matters too. A shared courtyard is not the same as a locked balcony. If the building has no gate or camera, don't leave anything you can't afford to lose. Use a lockable storage box, cable locks for chairs, or bring cushions inside. It's also smart to label your items and keep receipts.
Neighbors are part of the equation. A small, tidy setup usually causes fewer complaints than a sprawling arrangement that blocks common space. Avoid leaving ashtrays, food, or wet towels out. If the furniture is for everyone, make that clear; if it's personal, keep it compact and easy to move.
So yes, you can often leave urban outdoor furniture in a shared apartment courtyard, but do it responsibly. Check the rules, choose weatherproof and secure pieces, keep walkways clear, and be considerate. If you're unsure, ask management in writing and keep the answer. That way your courtyard chairs are a nice amenity, not a source of conflict.