Aho was born in Veteli, Finland. He was known by the nickname "Kannuksen Kennedy" ("The Kennedy of Kannus", Kannus being his hometown) due to his streamlined and well coiffed habitus, a comparison with United States President John F. Kennedy.
Aho was from 1990 to 2002 the chairman of the Centre Party (one of the three major Finnish political parties, somewhat on the conservative side of the centre). He was a member of the Finnish eduskunta (parliament) from 1983 to 2003.
Aho was the prime minister of conservative government (Centre Party, National Coalition Party, Christian Democrats and Swedish People's Party) from 1991 to 1995. He is best known for leading Finland into the European Union. Aho's own party, gaining most of its support from rural areas, opposed the EU membership, but was persuaded behind it due to prime minister's diplomacy. Aho's government faced also the deep economic depression of the early 1990s. Its stringent cut-and-save policy and its plans to lower unemployment rate made it unpopular, which partly caused its fall in the 1995 election and Centre Party's eight-year period in opposition.
Esko Aho lost the bid for President of Finland to Tarja Halonen in 2000. After that he retired from active politics in the early initially through a "sabbatical leave" of one year to lecture at Harvard University. In the 2003 election he left parliament and retired from daily politics. Currently he serves as the president of the SITRA, the Finnish National Fund for Research and Development.
It was announced by Nokia Oyj in August 2008 that Aho would be joining Nokia as Head of Corporate Relations and Responsibility and become a member of its executive board, he will take up these positions on January 1st 2009.
At the time of his rise to Prime Minister, he was the youngest head-of-government in Europe.
Member of the Club of Madrid.