Niilo Heikki Antero Leppo (8 November 1906 Vihti – November 16, 1987) was a Finnish diplomat. He worked in Switzerland from 1946 to 1948 as Chargé d'Affaires of Finland.[1] He was appointed Envoy to Buenos Aires in 1955 and in 1957 he received the ambassador's status.
From 1961, he was the rapporteur for the ambassadors.[2] and 1964-1974 Finland's Ambassador to Brazil[3]
His brother was economist Matti Leppo.[2]