Alfonzo is a given name and surname. Notable people with the name include:

Surname

• Alfredo Armas Alfonzo (1921–1990), Venezuelan writer, critic, editor and historian
• Carlos Alfonzo, Cuban-American painter
• DeJuan Alfonzo (born 1977), American football wide receiver/linebacker
• Edgardo Alfonzo a.k.a. "Fonzie" (born 1973), Major League Baseball infielder
• Eliézer Alfonzo (born 1979), professional baseball catcher
• José Luis Alfonzo (born 1961), Argentinian film actor
• Juan Pablo Perez Alfonzo (1903–1979), Venezuelan diplomat, politician and lawyer

Given name

• Alfonzo Dennard (born 1989), American football cornerback
• Luis Alfonzo García (born 1978), professional baseball first baseman
• Alfonzo Giordano (1937–2013), senior ranking officer in the Philadelphia Police Department, convicted of accepting bribes
• Alfonzo Graham (born 2000), American football player
• Luis Alfonzo Larrain (1911–1996), Venezuelan composer, music director and producer
• Alfonzo Ratliff or Alfonso Ratliff (born 1956), American boxer
• Alfonzo Sturzenegger (1888–1949), American football and baseball player and coach

• Alfonzo Frohicky, a character in Ninjago

• Afono
• Alfoz
• Alonzo (disambiguation)