Foreign relations of Saudi Arabia are the diplomatic and trade relations between Saudi Arabia and other countries around the world. The foreign policy of Saudi Arabia is focused on co-operation with the oil-exporting Gulf States, the unity of the Arab World, Islamic solidarity, and support for the United Nations. In practice, the main concerns in recent years have been relations with the US, the Saudi Arabian–led intervention in Yemen, the Israeli–Palestinian conflict, Iraq, the perceived threat from the Islamic Republic of Iran, and the effect of oil pricing. Saudi Arabia contributes large amounts of development aid to Muslim countries. From 1986 to 2006, the country donated £49 billion in aid.

Although a member of the Non-Aligned Movement, Saudi Arabia is described as leading the "Pro-Western Camp" of Arab countries, aligned with the U.S. and composed of Egypt, Jordan, and Arab states of the Persian Gulf. Saudi Arabia and the United States are close strategic allies and partners. However, the relationship witnessed certain decline during the last years of the Obama administration, but strengthened following the election of President Donald Trump who forged close ties with the Saudi royal family. Sunni Islam is the main religion of Saudi. China and Saudi Arabia are major allies, with the relationship between the two countries growing significantly in recent decades. A majority of Saudi Arabians have expressed a favorable view of China.

As a founding member of OPEC, Saudi Arabia's long-term oil pricing policy has been to keep prices stable and moderate—high enough to earn large amounts of revenue, but not so high as to encourage alternative energy sources among oil importers, or jeopardise the economies of Western countries where many of its financial assets are located and which provide political and military support for the Saudi government. The major exception to this occurred during the 1973 oil crisis when Saudi Arabia, with the other Arab oil states, used an embargo on oil supplies to pressure the US to stop supporting Israel.

Saudi Arabia is a founding member of several multinational organizations, including OPEC, the United Nations, the Arab League. It is also a founding member of the Gulf Cooperation Council, Muslim World League, the Organisation of Islamic Cooperation, and the Islamic Development Bank—all of which are headquartered in Saudi. The country plays a prominent role in the International Monetary Fund, the World Bank, and in 2005 joined the World Trade Organization.

According to a UCLA professor James L. Gelvin, Saudi Arabia recently has become much more active in terms of foreign and security policy because of the Arab Spring, the policies of the Obama administration and the mid-2010s collapse of oil prices.

After World War II (1939–1945) and during the Cold War (1945–1992), Saudi Arabia maintained an anti-Communist, anti-secular Arab-nationalist policy, often working with the leading anti-communist power, the United States. Following the 1973 oil crisis, when Saudi Arabia and other Arab oil exporters embargoed the United States and its allies for their support of Israel, oil revenues increased dramatically, and the Kingdom worked to become the leading Islamic state, spending generously to advance Islam and particularly its conservative school (known as Wahhabism). Supporters see this as having purified and unified the Islamic faith; other commentators claim it has eroded regional Islamic cultures. (Examples of the acculturizing effect of Saudi aid can be seen among the Minangkabau and the Acehnese in Indonesia, as well as among the people of the Maldives. The Wahhabi form of Islam is also perceived in the West as a source of Islamist extremism.

Saudi Arabia and its oil policy were significant factors in the proxy wars of the Cold War prior to the downfall of Soviet Communism in the late 1980s and early 1990s. Saudi Arabia helped to finance not just the Afghan Mujahideen but also non-Muslim anti-communists. It also seriously harmed the Soviet Communist cause by stabilizing oil prices "throughout the 1980s, just when the Russians were desperate to sell energy in order to keep up with huge hikes in American military spending."

Following King Fahd's stroke in 1995, Abdullah, then Crown Prince, assumed responsibility for foreign policy. A marked change in U.S.-Saudi relations occurred, as Abdullah sought to put distance between his policies and the unpopular pro-Western policies of King Fahd. Abdullah took a more independent line from the US and concentrated on improving regional relations, particularly with Iran. Several long-standing border disputes were resolved, including significantly reshaping the Saudi border with Yemen. The new approach resulted in increasingly strained relations with the US. Despite this, the U.S. and Saudi Arabia remained close. In 1998 Abdullah paid a state visit to Washington and met with U.S. President Bill Clinton.