Arnoldo is an Italian and Spanish masculine given name. It is the Italian and Spanish spelling of Arnold. Notable people with the name include:
First name Arnoldo Alemán (born 1946), Nicaraguan politician Arnoldo José Avilés García (born 1968), Honduran politician Arnoldo Berruti (1902–1967), Italian water polo player Arnoldo Camu (1937–1973), Chilean lawyer and political activist Arnoldo Castillo (1922–2005), Argentine politician Arnoldo Castro (1939–2023), Mexican baseball player Arnoldo de Winkelried Bertoni (1878–1973), Paraguayan zoologist Arnaldo Ferraguti (1862–1925), Italian painter Arnoldo Ferreto, 20th-century Costa Rican politician Arnoldo Foà (1916–2014), Italian actor Arnoldo Frigessi (born 1959), Italian statistician and academic Arnoldo Gabaldón (1909–1990), Venezuelan physician and politician Arnoldo Granella (1939–2022), French football player Arnoldo Herrera (born 1996), Costa Rican swimmer Arnoldo Iguarán (born 1957), Colombian football player Arnoldo Jimenez (born 1982), American fugitive Arnoldo Kraus (1951–2025), Mexican physician and academic Arnoldo López Echandi (born 1941), Costa Rican politician Arnoldo Martínez Verdugo (1925–2013), Mexican politician Arnoldo Mondadori (1889–1971), Italian publisher Arnoldo Ochoa González (born 1951), Mexican politician Arnoldo Ortelli (1913–1986), Swiss footballer Arnoldo Parés (born 1922), Argentine boxer Arnoldo Pekelharing (1936–2001), Argentine sailor Arnoldo Penzkofer (1959–2008), Paraguayan basketball player Arnoldo Rábago (born 1942), Mexican sailor Arnoldo Rueda Medina (born 1969), Mexican drug trafficker Arnoldo Sartorio (1853–1936), German composer Arnoldo André Tinoco (born 1961), Costa Rican politician and diplomat Arnoldo Torres, American journalist Arnoldo Vizcaíno, 21st-century Mexican politician
Middle name Adolfo Arnoldo Majano (born 1938), Salvadoran military and political figure