Saudi Arabia is a high-income developing economy highly reliant on its petroleum sector. Oil and gas account for approximately 22.3% of Saudi GDP and 55% of government revenue, with substantial fluctuations depending on oil prices each year.

The kingdom has the second-largest proven petroleum reserves, and the fourth-largest measured natural gas reserves. Saudi Arabia is currently the largest exporter of petroleum in the world. Other major parts of the economy include refining and chemical manufacturing from the oil reserves, much of which is vertically integrated in the state-owned enterprise, Saudi Aramco. Saudi Arabia is a permanent and founding member of OPEC.

In 2016, the Saudi government launched its Saudi Vision 2030 program to reduce its dependency on oil and diversify its economic resources. By 2022, Saudi Arabia had only modestly reduced its dependence on oil. Monetary policy in Saudi Arabia is anchored by the fixed exchange rate of the Saudi Riyal to the U.S. Dollar. Nearly every major business in Saudi Arabia has extensive ties to the Saudi State.

Saudi oil reserves are the second largest in the world (after Brazilian–Venezuelan oil reserves), and Saudi Arabia is the world's leading oil exporter and second-largest oil producer. Proven reserves, according to figures provided by the Saudi government, are estimated to be 260 billion barrels (41 km³), which is about one-quarter of the world oil reserves. Petroleum in Saudi Arabia is not only plentiful but also located under pressure close to the earth's surface, which makes it less expensive and more profitable to extract compared to other places. The petroleum sector accounts for roughly 87% of Saudi budget revenues, 90% of export earnings, and 42% of GDP. Saudi Arabia's oil reserves and production are largely managed by the state-owned corporation Saudi Aramco.

Another 40% of the GDP comes from the private sector. An estimated 7.5 (2013) million foreigners work legally in Saudi Arabia and play a crucial role in developing the Saudi economy, for example in the oil and service sectors. The government has been encouraging the growth of the private sector for many years to decrease the kingdom's dependence on oil and to increase employment opportunities for the swelling Saudi population. In recent decades, the government started allowing private sector activity and foreign investor participation in certain sectors, such as power generation and telecommunications, and acceded to the World Trade Organization. During much of the 2000s, high oil prices allowed the government to post budget surpluses and boost spending on job training and education, infrastructure development, and government salaries.

With its absolute monarchy, large state sector, and supply of welfare benefits, the Saudi economy has been described asː

A bewildering (at least to outsiders) combination of a feudal fealty system and a more modern political patronage one. At every level in every sphere of activity, Saudis maneuver through life manipulating individual privileges, favours, obligations, and connections. By the same token, the government bureaucracy is a maze of overlapping or conflicting power centers under the patronage of various royal princes with their own priorities and agendas to pursue and dependents to satisfy.

The following table shows the main economic indicators in 1980–2021 (with IMF staff estimates in 2022–2027). Inflation under 5% is in green.