Malaysia is a country in Southeast Asia. The federal constitutional monarchy consists of 13 states and three federal territories, separated by the South China Sea into two regions: Peninsular Malaysia and Borneo's East Malaysia. Peninsular Malaysia shares a land and maritime border with Thailand and maritime borders with Singapore, Vietnam, and Indonesia. East Malaysia shares land and maritime borders with Brunei and Indonesia, as well as a maritime border with the Philippines and Vietnam. Kuala Lumpur is the national capital, the country's largest city, and the seat of the legislative branch of the federal government. Putrajaya is the administrative centre, which represents the seat of both the executive branch and the judicial branch of the federal government. With a population of over 33 million, the country is the world's 43rd-most populous country. Malaysia is tropical and is one of 17 megadiverse countries; it is home to numerous endemic species. Tanjung Piai in the Malaysian state of Johor is the southernmost point of continental Eurasia.

Southeast Asia is the geographical south-eastern region of Asia, consisting of the regions that are situated south of China, east of the Indian subcontinent, and north-west of mainland Australia which is part of Oceania. Southeast Asia is bordered to the north by East Asia, to the west by South Asia and the Bay of Bengal, to the east by Oceania and the Pacific Ocean, and to the south by Australia and the Indian Ocean. Apart from the British Indian Ocean Territory and two out of 26 atolls of Maldives in South Asia, Maritime Southeast Asia is the only other subregion of Asia that lies partly within the Southern Hemisphere. Mainland Southeast Asia is entirely in the Northern Hemisphere. East Timor and the southern portion of Indonesia are the parts of Southeast Asia that lie south of the Equator.