Khawr al Udayd, (Arabic: خور العديد) also spelled Khor al Adaid, is a settlement and inlet of the Persian Gulf located in Al Wakrah Municipality in southeast Qatar, on the border with Saudi Arabia. It is known to local English speakers as the "Inland Sea".
Khawr al Udayd had served as a refuge for pirates from Abu Dhabi during the 19th century. Members of the Bani Yas tribe migrated and settled in the area on two separate occasions: 1835 and 1849. One of the more notable settlers in 1835 was the pirate Jasim bin Jabir, who was joined there by his crew. The residents of eastern Qatar abetted the pirates of Khawr al Udayd in their pillaging of vessels off the coast of Abu Dhabi, resulting in a British naval force being sent to the settlement in 1836 to accost the piratical acts. The British ordered the chiefs of major Qatari towns to immediately desist from sending supplies to the pirates and instructed them to seize the pirate's boats. Additionally, the British naval force set fire to one of the pirate's vessels. As a result, Jassim bin Jabir relocated to Doha in September 1836. After receiving approval from the British in May 1837, the ruler of Abu Dhabi sent his troops to sack the town; 50 of its inhabitants were killed and its houses and fortifications were dismantled during the event.
In the mid-1800s, the settlement at Khawr al Udayd was inhabited by approximately 200 Bani Yas tribesmen who owned a total 30 pearling ships. The area was well protected, containing a small fort with two towers in the center of the town.
In 1878, the British and the Abu Dhabi government concocted a plan to invade Khawr al Udayd in order to curtail the piracy of its inhabitants. In response, Jassim bin Mohammed Al Thani threatened to occupy Khawr al Udayd, as he had perceived the proposed military excursion to be in violation of Qatar's territorial integrity. This culminated in an all-out war between Abu Dhabi and Qatar which lasted until the late 1880s.
As of the 2010 census, the settlement comprised 14 housing units and 4 establishments. There were 42 people living in the settlement, of which 100% were male and 0% were female. Out of the 42 inhabitants, 100% were 20 years of age or older and 0% were under the age of 20. The literacy rate stood at 64.3%.