Sharjah (/ˈʃɑːrdʒə/; Arabic: ٱلشَّارقَة aš-Šāriqah, Gulf Arabic: aš-Šārja) is the third-most populous city in the United Arab Emirates, after Dubai and Abu Dhabi. It is the capital of the Emirate of Sharjah and forms part of the Dubai-Sharjah-Ajman metropolitan area. The emirate shares legal, political, military and economic functions with the other emirates of the UAE within a federal framework. Each emirate has jurisdiction over some functions such as civil law enforcement and provision and upkeep of local facilities. Sharjah has been ruled by the Al Qasimi dynasty since the 18th century.

The city is a center for culture and industry, and alone contributes 7.4% of the GDP of the United Arab Emirates. The city covers approximately 235 km² and has a population of over 1,800,000 (2022–2023). Sharjah has been officially named as a WHO healthy city. The 2016 edition of QS Best Student Cities ranked Sharjah as the 68th best city in the world to be a university student. Sharjah is regarded as the cultural capital of the UAE, and was the Islamic culture capital of 2014 and Sharjah World Book Capital for 2019 by UNESCO.

On 1 January 2022, Sharjah made history when its public sector adopted a four-day working week and a three-day weekend, becoming the first government sector in the Gulf region and the entire Middle East to fully adopt a four-day working week.

The origin of the name of Sharjah is unknown, with most common interpretations linking the origin of the word Sharjah to the word sharq (Arabic: شَرْق, lit. 'east') due to the fact that the city is located to the east of Dubai and Abu Dhabi, and that Sharjah was the easternmost settlement at the time.

However, other interpretations have disputed the origin of the name based on location, and suggested instead that it refers to the word shurūq (Arabic: شُروق, lit. 'sunrise'). Further theories have linked the name to a pre-Islamic idol called Abed Al Shareq that transformed into Sharjah. The origin of the word has also been linked to the Andalusi Arabic usage of the word, which was used to refer to a fort.

Sharjah was historically one of the wealthiest towns in this region with a settlement in existence for over 5000 years. In the early 18th century, the Huwayla tribe of the Qawasim clan established itself in Sharjah c. 1727, declaring Sharjah independent. On 8 January 1820, Sheikh Sultan I signed the General Maritime Treaty with Britain, accepting a protectorate to keep the Ottoman Turks out. Like its neighbors Ajman, Dubai, Ras Al Khaimah, and Umm Al Quwain, Sharjah's position on the route to India made it important enough to be recognized as a salute state (be it of the lowest class: 3 guns).

In 1829, English author and traveler James Silk Buckingham described Sharjah as such:

"In the course of the night, we had passed the port of Sharjee, on the Arabian coast, which is not an island, Niebuhr's chart, the only one in which it is inserted; but a small town, on a sandy beach, containing from five to six hundred inhabitants. It is situated in lat. 25° 34' north, and lies eleven leagues south-west of a small island, close to the shore, called Jeziret-el-Hamra; and three leagues south-west of Sharjee is Aboo Hayle."