Ketuanan Melayu (Jawi: كتوانن ملايو‎; lit. "Malay Overlordship" or "Malay Supremacy") is a political concept that emphasises Malay hegemony and preeminence in present-day Malaysia. The Malaysian Malays have claimed a special position and special rights owing to their longer history in the area and the fact that the present Malaysian state itself evolved from a Malay polity. The oldest political institution in Malaysia is the system of Malay rulers of the nine Malay states. The British colonial authorities transformed the system and turned it first into a system of indirect rule, then in 1948, using this culturally based institution, they incorporated the Malay monarchy into the blueprints for the independent Federation of Malaya.

The term Tanah Melayu in its name, which literally means "Malay homeland", assumes proprietorship of the Malay states. In this method, the colonial government strengthened Malay ethno-nationalism, Malay ethnicity and culture and Malay sovereignty in the new nation-state. Though other cultures would continue to flourish, the identity of the emerging political community was to be shaped by the "historic" political culture of its dominant Malay ethnic group. The Chinese and Indian immigrants, who form a significant minority in Malaysia, are considered beholden to the Malays for granting them citizenship in return for special privileges as set out in Article 153 of the Constitution of Malaysia. This quid pro quo arrangement is usually referred to as the Malaysian social contract. The concept of ketuanan Melayu is usually cited by politicians, particularly those from the United Malays National Organisation (UMNO).

The phrase Ketuanan Melayu did not come into vogue until the early 2000s decade. Historically, the most vocal political opposition towards the concept has come from non-Malay-based parties, such as the Malaysian People's Movement Party (Parti Gerakan Rakyat Malaysia) and Democratic Action Party (DAP); in the 2000s decade, the multiracial (Parti Keadilan Rakyat, or PKR) also positioned itself against Ketuanan Melayu, advocating instead Ketuanan Rakyat (supremacy of the people). The idea of Malay nationalism gained attention in the 1940s, when the Malays organised themselves to protest the Malayan Union's establishment by the British, and later fought for independence. During the 1960s, there was a substantial effort challenging Malay nationalism led by the People's Action Party (PAP) of Singapore — which was a state in Malaysia from 1963 to 1965 — and the DAP after Singapore's expulsion. However, the portions of the Constitution related to Malay nationalism were "entrenched" after the race riots of 13 May 1969, which followed an election campaign focused on the issue of non-Malay rights and Malay nationalism. This period also saw the rise of "ultras" who advocated for a Malay supremacist one-party state led by UMNO, and an increased emphasis on the Malays being the "definitive people" of Malaysia — i.e., only a Malay could be a true Malaysian.

The riots caused a major change in the government's approach to racial issues, and led to the introduction of an aggressive affirmative action policy strongly favouring the Malays, the New Economic Policy (NEP). The National Culture Policy, also introduced in 1970, emphasised an assimilation of the non-Malays into the Malay ethnic group. During the 1990s, Prime Minister Mahathir Mohamad toned down this approach, with his Bangsa Malaysia policy emphasising a Malaysian instead of Malay identity for the state. However, since the 2010s, politicians particularly from the Malaysian United Indigenous Party (BERSATU) and the Malaysian Islamic Party (PAS) began re-emphasising the phrase, as they deemed such rights as being threatened under a Pakatan Harapan (PH)–led government, and publicly chastised government ministers from the coalition who questioned the concept as being in violation of the supposed social contract.

Ethnic Malays which make up the majority population of Malaysia at 70.4%, are an ethnic group of Austronesian peoplepredominantly inhabiting the Malay Peninsula, including the southernmost parts of Thailand, the east coast of Sumatra, the coast of Borneo, and the smaller islands which lie between these locations. The true origin of ethnic Malays is still the subject of studies among historians, anthropologists and linguists. A popular theory suggested that the people who spoke Austronesian languages first arrived in Maritime Southeast Asia between 2,500BCE and 1,500BCE, as a part of Austronesian expansion from Taiwan to Southeast Asia.

However, a recent genetic studies carried out by HUGO (Human Genome Organisation) involving almost 2,000 people across Asia, points to another theory of Asian migration pattern. The HUGO findings support the hypothesis that Asia was populated primarily through a single migration event from the south and that the South East Asian region was populated first which contained the most diversity, then continuing slowly North with its diversity being lost.

Hindu and Buddhist influences arrived through trade contacts with the Indian subcontinent. The beginning of the first Millennium saw the rise of ancient Malay states in the coastal areas of Malay Peninsula, notably the Red Earth Kingdom (1st century), Gangga Negara (2nd century), Langkasuka (2nd century), Kedah (2nd century) and Pahang (5th century). Between 7th and 13th centuries, many of these small, often prosperous peninsular maritime trading states became part of the Srivijaya empire, a kingdom centred in Palembang, Sumatra.

By the 15th century, the Malacca Sultanate, whose hegemony reached over much of the western Malay archipelago, had become the centre of Islamization in the east. The Malaccan tradition was transmitted onwards and fostered a vigorous ethos of Malay identity. Since this era, the Islamic faith became closely identified with Malay society and played a significant role in defining the Malay identity. The close identification of the Malays with Islam continued until the 20th century and was finally entrenched in the Article 160 of the Constitution of Malaysia as well as in the national philosophy of Brunei known as the Malay Islamic Monarchy.