Much of Gayoom's early life was spent in Egypt. He was among the 15 students selected at the direction of the then-president Mohamed Amin Didi for special education overseas. At the age of 10, he left for Egypt on 15 September 1947, with a stopover in Ceylon for a few days. However, his departure from Ceylon was delayed for two and a half years because of the 1948 Arab-Israeli War, during which he completed his secondary education at Royal College, Colombo. When the war ended, he left for Egypt in March 1950 along with other Maldivian students.
Gayoom attended Al-Azhar University in Egypt. He spent six months learning Arabic so he could enroll in the Faculty of Sharia and Civil Law to study for a Diploma of Education. In 1966, he obtained his Bachelor's degree in Islamic Sharia and Civil Law, with honors. Gayoom came out first in the Faculty of Islamic Law and Studies at Al-Azhar University and was awarded his graduation certificate by Gamal Abdel Nasser.He was later awarded Masters degree in Islamic Sharia. He completed English Language course from the American University in Cairo.
When fourteen Maldivian students, under Gayoom's direction, sent a signed letter to Prime Minister (later President) Ibrahim Nasir to reconsider his decision to establish diplomatic ties with Israel, their government-awarded grants were stopped. The students were then financed by the Egyptian government. By the time Gayoom acquired his MA in 1966, the Egyptian government had stopped its funding. As a result, he was unable to complete his PhD. Later, with his marriage, he decided not to go further with his studies.
As a result of being "blacklisted" by the government for his letter, Gayoom decided not to go home. He spent almost 24 years outside the Maldives except for a brief period in 1964. In 1967, he began working for the American University in Cairo as a research assistant in Muslim History under Professor Marsden Jones for almost 2 years.
In 1965, Gayoom met Nasreena Ibrahim, a student who had just arrived in Cairo from the Maldives for her studies. She was then 15 and Gayoom was 27. Four years later, they married in Cairo, on 14 July 1969. A few weeks after his marriage, he joined Ahmadu Bello University in Kano, Nigeria as a lecturer in Islamic Studies and moved there with Nasreena. In 20 March 1970, at the age of 20, Nasreena gave birth to twins, Dhunya Maumoon and Yumna Maumoon. When Nasreena got pregnant for the second time, it was arranged to send her to Malé. She gave birth to their first son, Farish, in Malé, on 31 March 1971. Nine years later, during Gayoom's presidency, Ghassan was born on 12 June 1980.
During his time in Egypt, he had become particularly interested in Egyptian politics. He closely followed the revolutionary movement led by the Muslim Brotherhood and Free Officers Movement of Gamal Abdel Nasser. He attended several public meetings of Muslim Brotherhood where celebrated orators like Sayyid Qutb railed against Britain, imperialism and King Farouk's government. In July 1952, Gayoom was at the Muslim Brotherhood camp, on holiday, when Gamal Abdel Nasser took over in a bloodless military coup. In his book A Man for All Islands, biographer Royston Ellis wrote, "Maumoon regarded it as a privilege to be able to hear Sayyed Qutb"..
On 12 March 1973, Gayoom was placed under house arrest for criticising President Ibrahim Nasir's policies. He was tried in court and sentenced to banishment for four years on 14 May 1973. On 21 May, he was taken to Makunudhoo Island of Haa Dhaalu Atoll. After serving five months of his sentence, Gayoom was released on 13 October 1973 as a result of Nasir's amnesty following his re-election for another five-year term.
In 1974, Gayoom was appointed as under-secretary in the Telecommunications Department. After ten weeks, he was promoted to director of the department. During this period, he worked as a part-time teacher in some private schools, teaching Islam, Arabic and English.
On 28 July 1974, Gayoom was again arrested for criticising Nasir's policies. This time he was kept in solitary confinement in a prison in Malé nicknamed 'China garden' (Chinese fishermen were once detained there). This prison was later demolished in Gayoom's presidency and Islamic Centre was erected on the site. After 50 days in jail, he was set free in September 1974.
Six weeks later, he was appointed as special under-secretary in the office of then Prime Minister Ahmed Zaki. The post of Prime Minister was abolished with the removal and banishment of Ahmed Zaki from office, in 6 March 1975. With this decision, Gayoom's position disappeared as well and he was notified of his dismissal when he was in Colombo. However, when he returned from Colombo, he was made the Deputy Ambassador of the Maldives in Sri Lanka. In 1975, he was sent to the United Nations for two months as a member of the Maldives delegation. Upon his return, he was appointed under-secretary at the department of External Affairs. After nine weeks, he was appointed the Deputy Minister of Transport. One year later, he was tenured at the United Nations from September 1976 to January 1977, until Nasir summoned him back at the end of the UN session. In 29 March 1977, Gayoom was appointed as Minister of Transport, making him a member of Nasir's cabinet. He held the post until 10 November 1978.
Five months later, he was elected with 92.96% of the votes as the new President of the Maldives. The grand reception of his inauguration was held at Majeediyaa School on the night of 10 November 1978. In a 1983 referendum, he was re-elected by 96.62%, for a second term. He was last re-elected to a sixth five-year term in October 2003 with 90.28% of the vote; he was the sole candidate, having been chosen by the Majlis.
The President of the Maldives is both the Head of Government and Head of State, with very little distinction between the two roles, therefore Gayoom is also the Commander-in-Chief of the Maldivian armed forces, the Maldives National Defence Force. In a 2007 referendum, voters approved a presidential system with direct election of the president, the option favored by Gayoom, rather than a parliamentary system.