The party was formed in 2009 from the merger of the Free Democratic Party (FDP) and the Liberal Party. The radical Free Democratic Party, also called the 'Radicals', was Switzerland's major establishment party. Founded in 1894, the party's classical liberal predecessors had governed Switzerland outright for most of the 19th century, and had been the guiding force behind the creation of modern Switzerland. The Liberal Party, known as the 'Old Liberals', represented the French-speaking establishment: again rooted in the conservative liberalism of the nineteenth century. It also had a distinctly liberal Protestant outlook.
In the 2003 federal election, the two parties formed an electoral alliance. In the election, the Liberals were reduced to four seats, below the five required to form an official grouping in the Federal Assembly, so the two formed a joint caucus. In June 2005, the two founded the
Radical and Liberal Union, which aimed to promote liberal goals through deeper cooperation. In 2007, the women's arms of the parties merged, while the youth wings merged the following year to form the Young Liberals. Agreement on the merger of the federal parties was agreed in October 2008. The agreement was adopted on 28 February 2009, applying retroactively to 1 January 2009. FDP President Fulvio Pelli of Ticino became the party's first leader, while Liberal President
Pierre Weiss was named one of four Vice-Presidents.
Separate Free Democrat and Liberal branches remained in competition with each other in Geneva, Valais, and Vaud. In May 2011, the party's two Geneva branches – Liberal Party of Geneva and Radical Party of Geneva – merged to form a single FDP.The Liberals cantonal branch. In the 2015 federal election, the FDP increased its share of the popular vote by 1.3%, the first time it had increased since the 1979 federal election.
Percentages of the FDP at district level in 2011