Siim Kallas is an Estonian former politician who served as Prime Minister of Estonia from 2002 to 2003 and as a European Commissioner from 2004 to 2014.

Otsason was born on 24 May 1931, in Tartu. After obtaining secondary education he came to study in Tallinn and graduated in 1954 from Tallinn Polytechnical Institute as an economist. He became one of