The Klang River is a river which flows through Kuala Lumpur and Selangor in Malaysia and eventually flows into the Straits of Malacca. It is approximately 120 km (75 mi) in length and drains a basin of about 1,288 km2 (497 sq mi). The Klang River has 11 major tributaries.

Kuala Lumpur, officially the Federal Territory of Kuala Lumpur and colloquially referred to as KL, is a federal territory and the capital city of Malaysia. It is the largest city in the country, covering an area of 243 km2 (94 sq mi) with a census population of 2,163,000 as of 2022. Greater Kuala Lumpur, also known as the Klang Valley, is an urban agglomeration of 8.622 million people as of 2023. It is among the fastest growing metropolitan regions in Southeast Asia, both in population and economic development. Klang Valley is ASEAN's fifth largest economy after Singapore, Jakarta, Bangkok, and Manila.