Ossi may refer to:
Organizations Open Source Seed Initiative, dedicated to maintaining access to plant genetic resources Open Source Software Institute, promoter of open-source software solutions in the US Federal, state and municipal government agencies
People Ossi (East Germans), a nickname given to former residents of the country East Germany (GDR) Ossian Ossi Blomqvist (1908–1955), Finnish speed skater Oskar "Ossi" Bonde (born 1979), the drummer of the rock band Johnossi Ossi Kauppi (1929–2000), Finnish ice hockey player Ossi Oikarinen (born 1970), Finnish engineer who works in Formula One Ossi Oswalda (1899–1948), German silent film actress Ossi Reichert (1925–2006), German Alpine skier Ossi Runne (1927–2020), Finnish conductor and composer Ossi Sandvik (born 1953), Finnish politician
Other uses Order of the Star of Italian Solidarity Ossi, Sardinia, a city in the province of Sassari, Sardinia
See also Ossie, a given name Ozzie, a given name