The Topkapı Palace (Turkish: Topkapı Sarayı) usually spelled is a palace in Istanbul, Turkey, which was the official and primary residence in the city of the Ottoman Sultans for approximately 400 years (1465-1856) of their 624-year reign.

The palace was a setting for state occasions and royal entertainments and is a major tourist attraction today, containing the most holy relics of the Muslim world such as the Prophet Muhammed's cloak and sword. Topkapı Palace is among those monuments belonging to the "Historic Areas of Istanbul", which became a UNESCO World Heritage Site in 1985, and is described in Criterion iv as "the best example[s] of ensembles of palaces of the Ottoman period.

Initial construction began in 1459, ordered by Sultan Mehmed II, the conqueror of Byzantine Constantinople. The palace is a complex made up of four main courtyards and many smaller buildings. At the height of its existence as a royal residence, the palace was home to as many as 4,000 people, formerly covering a larger area with a long shoreline. The complex has been expanded over the centuries, with many renovations such as after the 1509 earthquake and 1665 fire. It held mosques, a hospital, bakeries, and a mint. The name directly translates as "Cannon gate Palace", from the palace being named after a nearby gate, which has since been destroyed.