| Aarno Yrjö-Koskinen | |
| Office: | Minister of Foreign Affairs of Finland |
| Term Start: | 21 March 1931 |
| Term End: | 14 December 1932 |
| Predecessor: | Hjalmar J. Procopé |
| Successor: | Antti Hackzell |
| Office1: | Finnish ambasador to the Soviet Union |
| Term Start1: | 1 January 1931 |
| Term End1: | 8 April 1940 |
| Predecessor1: | Pontus Artti |
| Successor1: | Juho Kusti Paasikivi |
| Birth Date: | 9 December 1885 |
| Birth Place: | Helsinki, Grand Duchy of Finland |
| Death Place: | Helsinki, Finland |
| Resting Place: | Hietaniemi Cemetery |
| Nationality: | Russian |
| Party: | National Coalition Party |
| Alma Mater: | Imperial Alexander University |
| Profession: | Diplomat, civil servant |
Aarno Armas Sakari Yrjö-Koskinen (9 December 1885, Helsinki – 8 June 1951, Helsinki)[1] was a Finnish politician, Envoy and freiherr. He graduated as jurist and received the title varatuomari in 1915.
After the Finnish independence in 1917, Yrjö-Koskinen served under the Ministry for Foreign Affairs as Chief of political division from 1924 and Chief of staff from 1929. He worked as an Envoy in Moscow between 1 January 1931 and 8 April 1940.
Yrjö-Koskinen also served as the Minister of Foreign Affairs between 21 March 1931 and 15 December 1932.[2] During his ministry Yrjö-Koskinen signed on behalf of Finland the Soviet–Finnish Non-Aggression Pact with the Soviet Union. At beginning of the Winter War he moved from Moscow to the Finnish embassy in Ankara. Yrjö-Koskinen served in Turkey till 1950, and yet a small time in The Hague, the Netherlands.
Yrjö-Koskinen's father was the Finnish senator Yrjö Yrjö-Koskinen and grandfather was senator and historian Yrjö Sakari Yrjö-Koskinen.