In June 1959 the Del E. Webb Development Company paid over $20 million for 20,000 acres of the Marinette and Santa Fe ranches from the J.G. Boswell Company, on the site of the former ghost town of Marinette. A nationwide naming contest, with a new house as the prize, replaced the working name Marinette Retirement Community with Sun City. On opening weekend, January 1, 1960, about 100,000 people came, ten times the expected crowd, and the event landed on the cover of Time. Webb repeated the model with Sun City West in the late 1970s, Sun City Grand in the late 1990s, Sun City Anthem in 1999 and Sun City Festival in July 2006.

Sun City lies about 16 miles northwest of downtown Phoenix, with streets laid out in concentric circles that form four pinwheels. The 2020 census counted 39,931 residents with a median age of 72.6, just 1.2% under 18, and 45.9% of households made up of people living alone. The community has eight golf courses, seven recreation centers, the Sun Bowl amphitheater and lawn bowling greens that hosted the South Central Division of the 2019 U.S. Lawn Bowling Open. The Sun City Homeowners Association campaigned to keep the area unorganized school district territory to hold down property taxes, so the few local children attend Peoria Unified or Dysart Unified schools.

• Sun City Stadium opened in 1971, was the Milwaukee Brewers’ spring training home from 1973 to 1985 and was razed in 1995.
• A horizontal sundial built in 1973 and renovated in 2011 runs 64 feet long with a 36-foot gnomon.
• In Spur Industries v. Del E. Webb Development Co. in 1972, Arizona’s Supreme Court ordered a cattle feedlot to move but made Webb pay because it came to the nuisance.
• Archbishop Paul Marcinkus, president of the Vatican Bank from 1971 to 1989, lived in Sun City.
• Zuni Hills Elementary School belongs to the Peoria district but carries a Sun City postal address.