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 Strait of Malacca in the centre, a part of Sunda Strait in the south, and the western part of South China Sea in the east.

[4][5][6] Another Indian source, an inscription on the south wall of the Brihadeeswarar Temple, recorded the word Malaiur, referring to a kingdom in the Malay Peninsula that had "a strong mountain for its rampart".

[7][8] Ptolemy's Geographia named a geographical region of the Golden Chersonese as Maleu-kolon, a term thought to derive from Sanskrit malayakolam or malaikurram.

[9] While the Chinese chronicle of the Yuan dynasty mentioned the word Ma-li-yu-er, referring to a nation of the Malay Peninsula that was threatened by the southward expansion of the Sukhothai Kingdom under King Ram Khamhaeng.

[10][11] 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 the Yuan chronicle.

Several large endangered mammals inhabit the peninsula – Asian elephant (Elephas maximus), gaur (Bos gaurus), tiger (Panthera tigris), sun bear (Helarctos malayanus), Malayan tapir (Tapirus indicus), clouded leopard (Neofelis nebulosa), and siamang (Symphalangus syndactylus).

[16] The Sumatran rhinoceros (Dicerorhinus sumatrensis) once inhabited the forests, but Malaysia's last rhinoceroses died in 2019, and the species' few remaining members survive only in Sumatra.