Mahathir was born at his parents' home in a poor neighbourhood at Lorong Kilang Ais, Alor Setar, in the capital of the Malay sultanate of Kedah under a British protectorate, on 10 July 1925.

[29][32] With schools closed during the Japanese occupation of Malaya in World War II, he started a small business, selling coffee and snacks such as pisang goreng (banana fritters).

[40] With the money from his medical practice, Mahathir indulged in his entrepreneurial streak and invested in property development, tin mining, a franchised petrol station, and a shop to do quick printing–sometimes to rescue Malay businessmen in trouble.

[45] Elected to parliament in a volatile political period, Mahathir, as a backbencher, launched himself into the main conflict of the day: Singapore's future, with its large and economically powerful ethnic Chinese population, as a state of Malaysia.

Each of Abdul Razak's preferred candidates was elected: former Chief Minister of Melaka, Ghafar Baba; Tengku Razaleigh Hamzah, a wealthy businessman and member of Kelantan's royal family; and Mahathir.

[64][65] Mahathir's rivals had significant political liabilities: Ghazali, having been defeated by others for the vice-presidency, lacked the support of UMNO members; Ghafar had no higher education and was not fluent in English; and Razaleigh was young, inexperienced, and unmarried.

[72] In September 1978, Mahathir launched the Central Unit of the Federal Industrial Development Authority, a streamlined "one-stop agency" aimed at simplifying the application process for licences, permits, and facilities.

[73] Later that month, he led a 31-member trade delegation on a 20-day tour to the United States, aiming to attract American investors by highlighting opportunities in Malaysia, including tax exemptions and other incentives.

[87] Under calls from opposition leader Lim Kit Siang and others,[88] Musa Hitam, serving concurrently as Home Minister, lifted the ban on Mahathir's book The Malay Dilemma.

[92] This legislation, championed by Mahathir, not only unified the time zones of East and Peninsular Malaysia but also aligned the country with regional economic hubs such as Hong Kong, Manila, and Perth.

[95] Afterwards, he reinforced this vision by implementing measures such as requiring ministers to declare their assets, limiting land applications to one piece per leader, discouraging conflicts of interest with public-listed companies, and advising against ostentation and visits to nightclubs.

[96] Mahathir further emphasized this vision by launching the "Leadership-by-Example" campaign in 1983 at Stadium Tun Razak, Kuala Lumpur, encouraging leaders and civil servants to uphold integrity, professionalism, and ethical behavior in order to inspire public trust and ensure that national objectives were achieved through exemplary conduct.

The position of Yang di-Pertuan Agong, the Malaysian head of state, was due to rotate into either the elderly Idris Shah II of Perak or the controversial Iskandar of Johor, who had only a few years earlier been convicted of manslaughter.

[111] In 1986, Australians Kevin Barlow and Brian Chambers became the first Westerners executed under Malaysia’s mandatory death penalty for drug trafficking, despite last-minute clemency appeals from Australia and the United Kingdom.

Tensions escalated following a protest by UMNO’s Youth wing, leading Mahathir to launch Operation Lalang, during which 119 individuals, including opposition figures, were detained, and three newspapers were temporarily suspended.

[134] The negotiations, overseen by Special Branch chief Abdul Rahim Mohd Noor,[132] were later documented in Colin Abraham's The Finest Hours, which included a foreword written by Mahathir himself.

[152] The IMF's 1999 Article IV consultation report acknowledged that Malaysia's capital controls and exchange rate peg, initially met with skepticism, had produced more positive results than expected.

[190] In a shift from his predecessors, Mahathir frequently condemned Israel and ensured Malaysian support for the Palestine Liberation Organization, although toned down his criticisms after the Oslo Accords were agreed.

[200][186] Under "Look East", Mahathir particularly prioritised relations with Japan, hoping this would bolster Malaysia's economy and that Japanese work ethic, values and moral norms would have a positive influence on Malaysians.

[203] In 1985, Mahathir visited China for the first time as Prime Minister, where he met Chinese leader Deng Xiaoping, establishing a new level of trust that laid the foundation for Malaysia-China relations and set the stage for decades of economic and diplomatic growth.

[218] In 1998, US vice-president Al Gore gave a speech expressing sympathy for the Reformasi movement at the Asia-Pacific Economic Cooperation (APEC) conference hosted by Malaysia, infuriating Mahathir and other ministers.

[223] In September 1981, shortly after Mahathir assumed office as Prime Minister, the country carried out the "Dawn Raid", a calculated operation orchestrated by Permodalan Nasional Berhad (PNB) to regain majority ownership of Guthrie, one of the largest British-owned plantation companies at the time.

[231] Key progress included enhanced trade, particularly in palm oil exports and British technology imports, as well as increased educational cooperation through scholarships for Malaysian students in the UK.

His administration oversaw the procurement of advanced military assets, including 18 Russian-made MiG-29N fighter jets and eight American-made F/A-18D Hornets, diversifying Malaysia’s defense partnerships beyond traditional suppliers.

[278] In 2006, Mahathir co-founded The Loaf bakery with Motoko Resources Sdn Bhd, opening its first store in Telaga Harbor, Langkawi, before expanding to 12 outlets in locations such as KLCC, Pavilion, Sogo, and Empire Shopping Gallery.

[282] Mahathir criticised the awarding of import permits for foreign cars, which he claimed were causing Proton's domestic sales to suffer,[283] and attacked Abdullah for cancelling the construction of a second causeway between Malaysia and Singapore.

[324][325] Mahathir promised to "restore the rule of law", and reopen investigations into the 1Malaysia Development Berhad scandal, telling the press that Najib would face consequences if found guilty of corruption.

[334][335] A year into his term, Mahathir's approval ratings had fallen as the economy slowed and several planned reforms, such as abolishing capital punishment and the Sedition Act 1948, were not realised amid divisions in the coalition.

[344] He visited Vladivostok for a meeting of the Eastern Economic Forum in late 2019, where he cast doubt on the Joint Investigation Team's findings related to the downing of Malaysia Airlines Flight 17.

Reflecting on the decision, he noted, “As a doctor myself, I understood the risks, including the possibility of not surviving, as the procedure was not common at the time.”[465] After his recovery, Mahathir left the country on March 12 for visits to London, Spain, and Morocco,[466] where he also met with the Spanish Prime Minister Felipe González.