Selangor ( /səˈlæŋə/) also known by its Arabic honorific, Darul Ehsan, or "Abode of Sincerity") is one of the 13 states of Malaysia. It is on the west coast of Peninsular Malaysia and is bordered by Perak to the north, Pahang to the east, Negeri Sembilan to the south and the Strait of Malacca to the west. It surrounds the federal territories of Kuala Lumpur and Putrajaya, both of which were once under Selangor's sovereignty.

The state capital is Shah Alam, the first city in Selangor, and the royal capital is Klang. Another major urban centre is Petaling Jaya which was awarded city status on June 20, 2006. Selangor is one of only two Malaysian states with more than one city; the other is Sarawak. Selangor has the largest city in Malaysia and it is growing rapidly due to modernization in the Klang Valley.^{[citation needed]}

Selangor is the richest state in Malaysia in terms of gross domestic product (GDP) per capita. This state is also the most developed in Malaysia with good infrastructure such as highways and transport. The state also has the largest population in Malaysia, with a high standard of living and the state's poverty rate is the lowest in the country.