Arnaldo is a given name. Notable people with the name include:
Arnaldo Abrantes (born 1986), Portuguese track and field sprinter
Arnaldo Alonso (born 1979), Paraguayan footballer
Arnaldo André (born 1943), soap-opera Paraguayan actor
Arnaldo Andreoli (1893–1952), Italian gymnast who competed in the 1920 Summer Olympics
Arnaldo Maria Angelini (1909–1999), Italian scientist, working with Italy's power generation
Arnaldo Antunes (born 1960), writer and composer from Brazil
Arnaldo Baptista (born 1948), Brazilian rock musician and composer
Arnaldo Villalba Benitez (born 1978), Paraguayan footballer
Arnaldo Bonfanti (born 1978), footballer
Arnaldo Carli (1901–1972), Italian racing cyclist and Olympic champion
Arnaldo Carvalho de Melo, Brazilian developer working on the Linux kernel
Arnaldo Cézar Coelho (born 1943), the first Brazilian to take charge of the FIFA World Cup final
Arnaldo Cohen, Brazilian pianist
Arnaldo da Silva (born 1964), former Brazilian athlete
Arnaldo de Oliveira Sales, GBM, OBE, JP, Chairman of the Hong Kong Olympic Academy
Arnaldo Deserti (born 1979), Italian water polo player
Arnaldo Edi Lopes da Silva (born 1982), Portuguese footballer of Guinea-Bissauan descent
Arnaldo Espínola (born 1975), Paraguayan footballer
Arnaldo Faustini (1872–1944), Italian polar geographer, writer, and cartographer
Arnaldo Ferraro (born 1936), former Republican Party politician from Brooklyn, New York
Arnaldo Forlani (born 1925), Italian politician and 44th Prime Minister of Italy
Arnaldo Freire, Brazilian guitarist, teacher, cultural producer and composer
Mario Arnaldo Gómez (born 1981), Honduran footballer
Arnaldo Jabor (born 1940), Brazilian film director, screenwriter and producer
Arnaldo Ramos Lauzerique, Cuban independent economist
Arnaldo Tamayo Méndez (born 1942), the first Cuban citizen to travel into earth orbit
Arnaldo Mesa (born 1967), retired boxer from Cuba and Olympic silver medallist
Arnaldo Momigliano KBE (1908–1987), Italian historian known for his work in historiography
Arnaldo Ochoa (1930–1989), Cuban general executed after being found guilty of treason
Arnaldo Ortelli, Swiss footballer and squad member for Switzerland in the 1934 FIFA World Cup
Arnaldo Otegi (born 1958), Basque politician, spokesman for the outlawed Abertzale Basque separatist party Batasuna
Arnaldo Ouana (born 1969), retired Mozambique international football player
Arnaldo Pérez (born 1958), former butterfly and freestyle swimmer from Puerto Rico
Arnaldo Pambianco (born 1935), Italian former professional road racing cyclist
Arnaldo Pereira (born 1985), Paraguayan footballer
Arnaldo Pomodoro, Italian sculptor
Javier Arnaldo Portillo (born 1981), Honduran football player
Arnaldo Orfila Reynal (1897–1997), Argentine chemist and academic
Arnaldo Ribeiro (1930–2009), Roman Catholic Archbishop in Ribeirão Preto, Brazil
Arnaldo Darío Rosado (1953–1978), activist for the independence of Puerto Rico from a very young age
Arnaldo Salvi (born 1915), Italian professional football player
Arnaldo Santos, Puerto Rican reggaeton and rock producer, singer and guitarist
Arnaldo Sentimenti (1914–1997), former Italian football player and coach
Arnaldo Silva (born 1944), former Portuguese footballer who played as midfielder
Arnaldo Villalba (born 1978), Paraguayan footballer
