Papaioannou () is a Greek surname. Notable people with the surname include:
Antonios Papaioannou (born 1877), Greek gymnast Charalampos Papaioannou (born 1972), Greek judoka Dimitris Papaioannou (born 1964), Greek choreographer, director, dancer and artist Dimitrios Papaioannou (born 2001), Greek footballer Eleana Papaioannou (born 1983), Greek singer-songwriter Ezekias Papaioannou (1908–1988), Cypriot politician George Papaioannou (1933–1999), Greek-American bishop Giannis Papaioannou (1913–1972), Greek songwriter Ioannis Papaioannou (chess player) (born 1976), Greek chess grandmaster Ioannis Papaioannou (actor) (1869–1931), Greek actor Konstantinos Papaioannou (1899–1979), Greek physicist and mathematician Lakis Papaioannou (born 1956), Greek footballer Loukas Papaioannou (1831–1890), Greek professor Makis Papaioannou (born 1977), Cypriot footballer Miltiadis Papaioannou (born 1947), Greek politician Mimis Papaioannou (1942–2023), Greek footballer Pantelis Papaioannou (1880s–1907), Greek leader of the Macedonian Struggle Pavlos Papaioannou (born 1959), Greek footballer Ramona Papaioannou (born 1989), Cypriot sprinter Sofia Papaioannou (born 1969), Greek journalist Virginia Papaioannou (born 1946), American biologist Voula Papaioannou (1898–1990), Greek photographer Yiannis Papaioannou (1910–1989), Greek composer