List of Famous people who are 90

Kushal Pal Singh is an Indian billionaire real estate developer, and the chairman and CEO of real estate developer DLF Limited, founded by his father-in-law Chaudhary Raghvender Singh. DLF has an estimated land bank of 10,255 acres (42 km²), with about 3,000 acres (12 km²) in Gurugram, called DLF City. Singh's personal wealth is estimated at $6.1 billion as per the 50 richest in Asia in Forbes 2017. In 2008, he was ranked the 8th richest person in the world in Forbes 2008. His autobiography, named Whatever the Odds: The Incredible Story Behind DLF, was published in 2011; Jack Welch spoke at the launch. According to Forbes India Rich list of 2019, he is the 25th richest Indian.

Wolfgang Demtröder is a German physicist and spectroscopist. He is the author of several textbooks on laser spectroscopy and a series of four textbooks on experimental physics. His books entitled Laserspektroskopie and Laser Spectroscopy are considered classics in the field. From 1970 til 1999, he was ordinary professor at Kaiserslautern University of Technology. Awarded the Max Born Prize in 1994.

Charles Weissmann is a Hungarian-born Swiss molecular biologist. Weissmann is particularly known for the first cloning and expression of interferon and his contributions to the unraveling of the molecular genetics of neurogenerative prion diseases such as scrapie, Creutzfeldt–Jakob disease and "mad cow disease".

Hans-Joachim Queisser is a solid-state physicist. He is best known for co-authoring the 1961 work on solar cells that detailed what is today known as the Shockley–Queisser limit, which is now considered the key contribution in this field.

Lowell Palmer Weicker Jr. is an American politician who served as a U.S. Representative, U.S. senator, and the 85th Governor of Connecticut. He unsuccessfully sought the Republican nomination for president in 1980. He was known as a very liberal Republican in Congress, causing conservatives to abandon him in the 1988 Senate election where he was replaced by a Conservative Democrat. Sometime after his defeat, Weicker was sent a letter by President Barack Obama thanking him for his work on the Americans with Disabilities Act in Congress. Though a member of the Republican Party during his time in Congress, he later left the Republican Party and became one of the few third party candidates to be elected to a state governorship in the United States in recent years, doing so on the ticket of A Connecticut Party.