Masing is a German and Estonian surname. Notable people with the surname include:
Ernst Johann Woldemar Masing (1836–1923), Baltic German philologist (et)
Gotthilf Leonhard Masing (1845–1936), Baltic German linguist (et)
Jaan Masing (1875–1948), Estonian politician and physician (et)
Johannes Masing (born 1959), German judge, jurisprudent and public law scholar
Karl Ernst Alexander Masing (1879–1956), Baltic German physician (et)
Oskar Masing (1874–1947), Baltic German philologist (de)
Otto Wilhelm Masing (1763–1832), Estonian linguist and clergyman
Uku Masing (1909–1985), Estonian philosopher, translator, theologist and folklorist
Viktor Masing (1925–2001), Estonian botanist and ecologist
Walter Masing (1915–1924), Baltic German physicist
