Katalin Szili was born 13 May 1956 in Barcs, Hungary
she is a former member of the Hungarian Parliament, who served as the Speaker of the National Assembly of Hungary from 2002 to 2009.
After obtaining a degree in law at Janus Pannonius University, she completed majors in human ecology and political science. She was a legislator from 1994 to 2014. Between 1994 and 1998 she was the political secretary of the Ministry of Environmental Protection and Water. Between 1998 and 2002 she served as Deputy Speaker of the Hungarian National Assembly.
She was the candidate of the Hungarian Socialist Party for presidency in the 2005 Hungarian presidential elections. Szili lost the election on 7 June 2005 to opposition nominee László Sólyom. The Hungarian Constitution prescribes that the President must be elected by the National Assembly of Hungary, thus the victory of the opposition came as something of a surprise. The junior coalition party, the Alliance of Free Democrats (SZDSZ), however, had long emphasized that it would not vote for a partisan President. Szili as a high-ranking member of the Socialist party was considered partisan, the SZDSZ abstained, enabling the more neutral candidate Sólyom (who was originally nominated by a non-governmental organization Védegylet and later supported by the opposition), to win the office. Another reason for the failed nomination was that SZDSZ was not consulted ahead of time and Szili lacked qualifications compared to Sólyom who previously held high office as the president of the Constitutional Court of Hungary. In 2009 Szili was the mayoral candidate of MSZP for the mayor of a major Hungarian city, Pécs. She lost the election to Zsolt Páva.
She came to be considered inner opposition inside the MSZP since 2009. In 2009 Szili resigned from her position as speaker of Parliament, She was succeeded by Béla Katona of MSZP. She formed the Movement of Alliance for the Future in 2010 and had her own candidates in some areas in the 2010 Hungarian parliamentary election. Szili was elected to the Parliament of Hungary via the Baranya County Party list where she was chairperson of the local MSZP branch.