Wouter Jacob Bos ((born July 14, 1963) is a retired Dutch politician of the Labour Party (PvdA) and management consultant. He served as a Member of the House of Representatives from May 19, 1998 until March 24, 2000 when he became State Secretary for Finance in the Cabinet Kok II following the resignation of Willem Vermeend who became Minister of Social Affairs and Employment. He returned to the House of Representatives on May 23, 2002 following the Dutch general election of 2002. The Labour Party suffered a landslide defeat in the election losing 23 seats, then Party leader Ad Melkert was blamed for the defeat and resigned. Bos announced his candidacy for the Labour Party leadership election and won by a landslide with 60% of the votes. Bos became the Labour Party party leader on November 19, 2002 and the Parliamentary leader of Labour Party in the House of Representatives on November 19, 2002 and became the lijsttrekker for the Dutch general election of 2003. The Labour Party was the largest winner of the election, gaining 19 seats (from 23 to 42) and became the second largest party in the House of Representatives. After a failed cabinet formation a new cabinet was formed with out the Labour Party. Bos served as opposition leader during the parliamentary period of the Cabinets Balkenende II and III. For the Dutch general election of 2006 Bos again as lijsttrekker lost 9 seats but the Labour Party remained the second largest party with 33 seats. The following cabinet formation resulted in a coalition agreement which formed the Cabinet Balkenende IV, comprising the Christian Democratic Appeal (CDA), Labour Party (PvdA) and the ChristianUnion (CU). Bos became Minister of Finance and Deputy Prime Minister, the cabinet took office on February 22, 2007. The cabinet fell on February 20, 2010 as the result of disagreement between CDA and Labour Party over the extension of ISAF mission in Afghanistan. Bos resigned his position as Party leader and retired from active politics.
Since his retirement from politics, Bos became a partner at the professional services firm KPMG and is also a consultant for the financial sector.