Jan Fischer was born in Prague in 1951 to a family of mathematical statisticians and actuarial mathematicians. His father was a scientific employee of the Mathematics Institute of the Czech Academy of Science and devoted himself to statistical applications in genetics, breeding and medicine.
Fischer finished his studies at the national economics faculty of the University of Economics, Prague with a degree in statistics and econometrics in 1974. He joined the statistical office after university, where he worked until the beginning of the 1980s as a research employee of the Research Institute of Socioeconomic Information (then a part of the statistics office). In 1985, he finished his post-graduate studies at the Prague School of Economics and gained the title of Candidate of Science in the field of economic statistics. He served in various functions at the Federal Statistical Office until 1990, when he became deputy chairman of the office. After the creation of an independent Czech Republic in 1993, he became the deputy chairman of the Czech Statistical Office.
From the beginning of the 1990s he led teams processing the results of parliamentary and municipal elections. He was also in charge of contacts with the European Union's Eurostat statistical office. In the spring of 2001, he worked on a mission of the International Monetary Fund which examined the possibility of building statistical services in East Timor.
From September 2000 he worked as the director of the production department for the Taylor Nelson Sofres Factum company, and from March 2002 until his naming as chairman of the Czech Statistical Office, he was the head of the research facilities of the Faculty of Informatics and Statistics of the Prague School of Economics.
He was named chairman of the Czech Statistical Office by the President of the Czech Republic on 24 April 2003.
He was named Prime Minister by the President of the Czech Republic on 9 April 2009.
He is a member of a number of prestigious institutions, including the Czech Statistics Society, the International Statistics Institute, the Science Council, the Board of Trustees of the University of Economics, Prague, as well as the Science Council of the University of J.E. Purkyně in Ústí nad Labem.
Jan Fischer is married for the second time and is the father of three children.