The Malay Peninsula (Malay: Semenanjung Tanah Melayu) is a peninsula in Southeast Asia. The land mass runs approximately north-south and, at its terminus, is the southernmost point of the Asian mainland. The area contains Peninsular Malaysia, Southern Thailand, and the southernmost tip of Myanmar (Kawthaung) as well as the city state Singapore, indigenous to or historically inhabited by the Malays, an Austronesian people.
The Titiwangsa Mountains are part of the Tenasserim Hills system, and form the backbone of the Peninsula. They form the southernmost section of the central cordillera which runs from Tibet through the Kra Isthmus (the Peninsula's narrowest point) into the Malay Peninsula. The Strait of Malacca separates the Malay Peninsula from the Indonesian island of Sumatra while the south coast is separated from the island of Singapore by the Straits of Johor.
The Malay term Tanah Melayu is derived from the word Tanah (land) and Melayu (Malays), thus it means "the Malay land". The term can be found in various Malay texts, of which the oldest dating back to the early 17th century. It is frequently mentioned in the Hikayat Hang Tuah, a well known classic tales associated with the legendary heroes of Malacca Sultanate. Tanah Melayu in the text is consistently employed to refer to the area under Malaccan dominance.
In the early 16th century, Tomé Pires, a Portuguese apothecary who stayed in Malaca from 1512 to 1515, writes an almost identical term, Terra de Tana Malaio which he referred to the southeastern part of Sumatra, where the deposed Sultan of Malacca, Mahmud Shah established his exiled government. The 17th century's account of Portuguese historian, Emanuel Godinho de Erédia, noted on the region of Malaios surrounded by the Andaman Sea in the north, the entire Malacca Strait in the centre, a part of Sunda Strait in the south, and the western part of South China Sea in the east.
Prior to the foundation of Malacca, ancient and medieval references to a Malay peninsula exist in various foreign sources. According to several Indian scholars, the word Malayadvipa ("mountain-insular continent"), mentioned in the ancient Indian text, Vayu Purana, may possibly refer to the Malay peninsula. Another Indian source, an inscription on the south wall of the Brihadeeswarar Temple, recorded the word Malaiur, referring to a kingdom in Malay peninsula that had "a strong mountain for its rampart". The Greek source, Geographia, written by Ptolemy, labelled a geographical part of Golden Chersonese as Maleu-kolon, a term thought to derive from Sanskrit malayakolam or malaikurram. While the Chinese chronicle of Yuan dynasty mentioned the word Ma-li-yu-er, referring to a nation of Malay peninsula that threatened by the southward expansion of Sukhothai Kingdom under King Ram Khamhaeng. During the same era, Marco Polo made a reference to Malauir in his travelogue, as a kingdom located in the Malay peninsula, possibly similar to the one mentioned in Yuan chronicle.. The Malay Peninsula was conflated with Persia in old Japan, and was known by the same name. 
In the early 20th century, the term Tanah Melayu was generally used by the Malays of the peninsula during the rise of Malay nationalism to describe uniting all Malay states on the peninsula under one Malay nation, although this ambition was largely realised with the formation of Persekutuan Tanah Melayu (Malay for "Federation of Malaya") in 1948.