George W. Van Tassel (1910–1978) was an American aviation worker who became one of the central figures of the 1950s contactee movement. From Giant Rock, a huge freestanding boulder in the Mojave Desert near Landers, California, he ran a small airport and cafe, hosted annual spacecraft conventions that drew thousands of people, relayed messages he attributed to beings from space and built the Integratron, a wooden dome he described as a machine for rejuvenation and time travel.

Van Tassel was born on March 12, 1910, in Jefferson, Ohio. He left school after the tenth grade, worked at a small airport near Cleveland and earned a private pilot's license, then moved to California around the age of 20. From 1930 to 1947 he worked as an aircraft mechanic and flight inspector for Douglas Aircraft, Hughes Aircraft and Lockheed. In 1947 he left the aerospace industry, leased land at Giant Rock from the Bureau of Land Management and moved there with his wife and three children, at first living in rooms the prospector Frank Critzer had dug beneath the rock. He built a cafe, a store, a gas station and the Giant Rock Airport, which he operated until 1975.

His contact claims began in the early 1950s. In I Rode a Flying Saucer (1952) he presented "cosmic wisdom" he said he had received from beings in outer space. Van Tassel said that in August 1953 the occupant of a spacecraft from Venus woke him, invited him aboard and gave him a technique for rejuvenating living tissue. He organized his teachings through the Ministry of Universal Wisdom and the College of Universal Wisdom, published their Proceedings from 1953 until his death, and wrote further books, including Into This World and Out Again (1956) and The Council of Seven Lights (1958).

The Giant Rock Spacecraft Conventions, held beside the boulder from 1953 for roughly two decades, became the movement's main gathering, with attendance put at about 10,000 at their 1959 peak; George Adamski spoke at the 1955 convention. Convention income, publications and donations helped pay for the Integratron, a 38-foot-high wooden dome that Van Tassel called "a time machine for basic research on rejuvenation, anti-gravity and time travel," and that he said drew on the work of Nikola Tesla and Georges Lakhovsky. He passed away in 1978 with the building unfinished. It was listed on the National Register of Historic Places in 2018, and its current owners offer "sound baths" inside.

On September 1, 2026, the Huntington Library in San Marino announced its first major ufology acquisition: the McKinney Collection of George W. Van Tassel Papers. According to LAist, it holds about 120 reel-to-reel tapes of his channelings, Integratron blueprints and a model of the building, photographs and records of his aviation career, and was assembled by Don McKinney, a Morongo Valley contractor who met Van Tassel as a teenager in 1969. The Huntington plans to show selections at its Strange Science event on October 30 and 31, 2026, bringing a figure long treated as desert lore into a research library's record of postwar California.