Martin Sean Indyk (born July 1, 1951) is a lobbyist and former United States ambassador to Israel. He is arguably best known as the framer of the U.S. policy of dual containment which sought to 'contain' Iraq and Iran, which he claimed were Israel's two most important strategic adversaries.

He was born to a Jewish family in London, England, but grew up and was educated in Australia, growing up in the Sydney suburb of Castlecrag. He graduated from the University of Sydney in 1972 and got a PhD in international relations from the Australian National University in 1977. He gained American citizenship in 1993. He was formerly married to Jill Collier Indyk with whom he had two children, Sarah and Jacob. His sister is an architect who resides in Sydney, Australia and has one son, Elan. His brother is an editor who resides in Sydney, Australia

In 1982, Indyk began working as a deputy research director for the American Israel Public Affairs Committee (AIPAC), a pro-Israel lobbying group in Washington. In 1985 Indyk served eight years as the founding Executive Director of the Washington Institute for Near East Policy, a research institute specializing in Arab-Israel relations and which was founded by AIPAC. He has also been an adjunct professor at the Johns Hopkins School of Advanced International Studies where he taught Israeli politics and foreign policy.