Naimi was born in ar-Rakah in the Eastern Province. He joined Saudi Aramco in 1947 as a twelve-year-old office boy. Under the training programs of Aramco, he studied at International College, Beirut and the American University of Beirut, before going to Lehigh University in the United States. He obtained a Bachelor of Science degree in geology in 1962. He then earned a Master of Science degree in hydrology and economic geology at Stanford University.

After graduation, Naimi continued to advance at Aramco. He became the supervisor for the Abqaiq production department in 1969. He was promoted to assistant Director and then Director of production in the Northern Borders Region (1972–1975). He became vice-president of production affairs in 1975. He was appointed vice President of petroleum affairs in 1978. Al Naimi was elected a member of board of Directors in 1980 and was promoted to the newly created position of executive vice-president of oil and gas affairs in 1981. He was named President of Saudi Aramco in 1983, being the first Saudi to hold that position. Later, after combining the presidency and chief executive position, he was appointed to each of these roles separately.

Also in 1995, Naimi received an Honorary Doctorate from Heriot-Watt University

Naimi was named one of the most influential people in the world by TIME magazine in 2008. In 2011, he was included in the inaugural 50 Most Influential ranking by Bloomberg Markets magazine. His autobiography was published in November 2016.

In December 2010, the Saudi Supreme Petroleum Council, chaired by King Abdullah, asked Naimi to nominate candidates to succeed him as oil minister.

In November 2014, still serving as Saudi oil minister and therefore the de facto leader of OPEC, Naimi became the primary advocate for the export organization's controversial new strategy. He argued that the oil market should be left to rebalance itself at lower price levels, strategically rebuilding OPEC's long-term market share by ending the profitability of high-cost US shale oil production. Naimi completed his Service as oil minister in May 2016, as deputy crown Prince Mohammed bin Salman took on a stronger role in Saudi oil policy.