The King's Cup, officially titled The Custodian of the Two Holy Mosques' Cup, is the Saudi Arabian football knockout cup competition.
The King's Cup is the second-oldest knockout competition in Saudi Arabian football, following the now-defunct Crown Prince Cup.
The competition was originally established in 1957 as the His Majesty's Cup (commonly known as the King Cup) and was held annually until 1990. After a hiatus, the tournament was reintroduced in 2008 under the new name King Cup of Champions, featuring the top six finishers of the Saudi Premier League, along with the winners of the Saudi Crown Prince Cup and the Saudi Federation Cup.
In 2014, the tournament was officially renamed the Custodian of the Two Holy Mosques' Cup and returned to a broader knockout format, more closely resembling the original structure.
In 2025, the Saudi football authorities revised the historical records of the King’s Cup following a comprehensive review and official documentation. As a result, certain titles that were previously classified as King’s Cup wins were reclassified as league championships, aligning with their original competitive structure. This adjustment led to changes in clubs' official title counts—some clubs gained additional league titles but saw a reduction in their number of cup titles.