The Night of Schmelzer was a debate in the House of Representatives of the Netherlands that took place from 13 October to the early hours of 14 October 1966. This night marked the final day of the general debate on the 1967 budget, which had begun on 11 October. During the debate's conclusion, Norbert Schmelzer, parliamentary group leader of the Catholic People's Party (KVP), introduced a motion opposing the Cals cabinet. This cabinet included members from the KVP, the Labour Party (PvdA), and the Anti-Revolutionary Party (ARP). Although the cabinet perceived the motion as a vote of no confidence, it passed nonetheless. Consequently, the cabinet resigned on 15 October.
The Night of Schmelzer catalyzed ongoing developments in Dutch politics. Within the Labour Party, distrust of the KVP deepened, spurring a polarisation strategy and the rise of the New Left faction. This event also accelerated the KVP's electoral decline, already underway due to depillarisation. Christian radicals favoring cooperation with the PvdA split from the KVP in 1968 to establish the Political Party of Radicals. Conversely, the Night propelled the KVP, CHU, and ARP toward unification as the Christian Democratic Appeal (CDA). Meanwhile, anti-establishment parties like the Farmers' Party and the newly-founded Democrats 66, established on 14 October 1966, gained momentum, reflected in their increased popularity in the 1967 general election.