Guy Maurice Marie Louise Verhofstadt (Dutch: [ˈɣi vərˈɦɔfstɑt] ^ⓘ; French: [ɡi vəʁɔfstad]; born 11 April 1953) is a Belgian politician who served as the prime minister of Belgium from 1999 to 2008. He was a member of the European Parliament (MEP) from Belgium from 2009 until 2024. Verhofstadt was a member of the Belgian Chamber of Representatives from 1985 to 2009. He served as deputy prime minister of Belgium and minister of Budget from 1985 to 1992. He was the prime minister of Belgium from 1999 to 2008. During this period, he gradually moved away from neoliberalism and became more of a centrist figure.

In the European Parliament, Verhofstadt was the leader of the Alliance of Liberals and Democrats for Europe (ALDE) from 2009 to 2019. In 2010, he co-founded the inter-parliamentarian Spinelli Group to support the creation of a European Federation. He was the ALDE Party nominee for President of the European Commission in the 2014 European Parliament election. He served as the European Parliament's Brexit Coordinator and Chair of the Brexit Steering Group from 2016 to 2020.

Born in 1953 in Dendermonde, Verhofstadt became president of the Liberaal Vlaams Studententverbond (Liberal Flemish Students' Association) (1972–1974), while studying law at the University of Ghent. He quickly became the secretary of Willy De Clercq, who was at that time the president of the Flemish liberal party (PVV). In 1982, at age 29, he became president of the party. In 1985, he was elected into the Chamber of Deputies, and became deputy prime minister and minister of budget under Prime Minister Wilfried Martens. Because of his economic views and his young age, he became known as "Baby Thatcher".

After being ousted from government, Verhofstadt became leader of the opposition. After a failed attempt to form a government in November 1991, he changed the PVV into the Flemish Liberals and Democrats (VLD). This new party attracted many politicians from other parties, notably from the Volksunie (VU) and the Christian People's Party (CVP). Despite the fact that many had high expectations, the party did not manage to outstrip the CVP. Verhofstadt resigned and disappeared from the political scene, only to return to the party's presidency in 1997, with a less radical image. He gradually moved away from neoliberalism (partly under the influence of his brother Dirk, a social liberal political philosopher), and became more of a centrist figure, a change which especially became clear during his first term as prime minister.

Partly because of a food scandal that broke out just before the 1999 elections, the VLD became the largest party in the country, obtaining over 22% of the vote in Flanders. He quickly formed a coalition with the Flemish socialists and greens and the French-speaking counterparts of these parties (a symmetric coalition) in Brussels and Wallonia. He was appointed prime minister on 12 July 1999, the first liberal to hold that office since 1938. It was the first Belgian government without a Christian Democratic party since 1958, and the first one to include green parties.

Verhofstadt was awarded the Vision for Europe Award in 2002 for his work toward a more unified Europe. The economic situation gave him leeway to raise the lowest social benefits and lower taxation. After 2001, the economic situation worsened. The 'Aging Fund' or 'Silver Fund' was set up, in order to ensure the maintenance of pensions until 2030.^{[citation needed]}

Much to the disapproval of his coalition partners, Verhofstadt and his VLD opposed granting the right to vote to non-EU residents. Instead, they proposed and were able to liberalise the procedure for obtaining Belgian citizenship. During the prelude to the Iraq crisis of 2003, Belgium joined France, Germany and Russia in opposition to the U.S.-led invasion of Iraq.

Following the 2003 Belgian federal election, Verhofstadt formed his second cabinet without the green parties, who were virtually annihilated in the election. For various reasons, the formation of the second government was delayed well beyond normal: the economic situation worsened to 1999 levels, both politically similar parties (liberals and socialists) gained approximately the same seats. Verhofstadt's second Government consisted of his liberal Open VLD their sister liberal MR, the Flemish social democratic SP.a and their sister social democratic party PS to form another Purple coalition.