Stikker entered politics in 1945, when he was elected to the Senate of the States General. On 23 March 1946, he co-founded the Partij van de Vrijheid (PvdV, Freedom Party), together with some former members of the pre-war Liberale Staatspartij (LSP, Liberal State Party). On 24 January 1948, the PvdV was absorbed by the Volkspartij voor Vrijheid en Democratie (VVD, Peoples Party for Freedom and Democracy), which is as of 2004 the country's most important Liberal party. Stikker was the VVD's first chairman.