Peninsular Malaysia (Malay: Semenanjung Malaysia; Jawi: سمننجڠ مليسيا), historically known as Malaya (Malay: Tanah Melayu; Jawi: تانه ملايو), also known as West Malaysia or the Malaysian Peninsula, is the part of Malaysia which occupies the southern half of the Malay Peninsula in Southeast Asia and the nearby islands. Its area totals 132,490 km2 (51,150 sq mi), which is nearly 40% of the total area of the country; the other 60% is East Malaysia. For comparison, it is slightly larger than England (130,395 Km2). It shares a land border with Thailand to the north  and a maritime border with Singapore to the south.
Across the Strait of Malacca to the west lies the island of Sumatra and across the South China Sea to the east lie the Natuna Islands of Indonesia. At the southern tip across the Strait of Johor lies the island country of Singapore. Peninsular Malaysia accounts for the majority (roughly 81.3%) of Malaysia's population and economy; as of 2017, its population is roughly 26 million (82% of total population).