Yes, you strictly need a ticket to enter the Castelo de São Jorge in Lisbon, Portugal. As of 2026, the standard adult ticket price is approximately €15, with discounts available for youth (ages 13–25), seniors over 65, and persons with disabilities. Children under 12 typically enter for free. Because the castle is one of Lisbon's most popular attractions, it is highly recommended to buy tickets online in advance to "skip the line" at the physical ticket office, which can have wait times exceeding an hour during the summer. Your ticket grants you access to the entire fortification, including the ramparts with panoramic city views, the archaeological site, and the "Camera Obscura" in the Tower of Ulysses. Note that if you have a Lisboa Card, entry is often fully included or significantly discounted, but you may still need to present the card at a designated kiosk to receive your entry pass.