See also: alto Alternative forms ALTO Etymology Borrowed from Spanish alto. Proper noun Alto (plural Altos) A surname. A census-designated place in Marin County, California, United States. (aerospace) initialism of air launch to orbit. Statistics According to the 2010 United States Census, Alto is the 28650th most common surname in the United States, belonging to 832 individuals. Alto is most common among White (67.07%) and Hispanic/Latino (13.34%) individuals. Anagrams ATOL, Toal, a lot, alot, atlo-, lota, talo-, tola