St. Augustine is the oldest continuously inhabited European-founded city in the United States, established in 1565.
Spanish admiral Pedro Menéndez de Avilés founded St. Augustine on September 8, 1565, in present-day Florida. The settlement was established decades before the English colonies at Jamestown and Plymouth. Spain built it to secure its claim in Florida and protect shipping routes connected with the Caribbean and the Atlantic.
The city changed hands between European powers and the United States over time, but its settlement endured continuously. The Castillo de San Marcos, begun in 1672, is a major surviving reminder of the Spanish colonial period and is the oldest masonry fort in the continental United States.
St. Augustine is sometimes confused with Jamestown, founded in 1607 as the first permanent English settlement in what became the United States. Santa Fe was founded by Spanish colonists in 1610. These distinctions matter because “oldest city” can mean oldest continuously inhabited European-founded city, oldest English settlement, or oldest settlement of another type.