Rio is the Spanish and Portuguese word for "river", best known from the city of Rio de Janeiro, and it is also used as a Japanese name with a range of meanings depending on the characters chosen. Its two letters and open sound fit the current taste for short, international boys' names. In the United States Rio climbed from number 1778 in 2000 into the top 1000 in 2020 and ranks number 532 among boys' names in 2025, close to its best rank of number 517 in 2024.