Gerardus 't Hooft (born July 5, 1946, Den Helder) is a professor in theoretical physics at Utrecht University, the Netherlands. He shared the 1999 Nobel Prize in Physics with Martinus J. G. Veltman "for elucidating the quantum structure of electroweak interactions". Asteroid 9491 Thooft is named in his honor; he has written a constitution for its future inhabitants. He was awarded the Lorentz Medal in 1986 and the Spinozapremie in 1995. Nobel Prize in Physics laureate Frits Zernike was his great-uncle.
The name 't Hooft means "the head" or "the main" ('t is short for "het"). He is married to Albertha Schik (Betteke) and has two daughters, Saskia and Ellen. Saskia is currently translating one of her father's popular Dutch fiction books 'Planetenbiljart' into English. The book's title will be 'Playing with Planets' and is expected to be in stores as of December 31, 2008.