The Reformed Political League (Dutch: Gereformeerd Politiek Verbond, GPV) was an orthodox Protestant political party in the Netherlands. The GPV is one of the predecessors of the Christian Union. The party was a testimonial party.

The GPV was founded in 1948 as the result of a theological conflict within the Reformed Churches in the Netherlands, which led to the creation of the Reformed Churches in the Netherlands (Liberated). In 1944 a group of orthodox Protestants left the Reformed Church, because they disagreed with Abraham Kuyper's view that God had created multiple branches of Christianity (Catholicism, Protestantism etc.), each with their own sphere.

In 1948, adherents of the Reformed Church in the Netherlands (Liberated) left the Anti-Revolutionary Party, the party linked to the Reformed Church in the Netherlands. On 1 April 1948, they founded the GPV during a congress Amersfoort. Former ARP MP Albertus Zijlstra chaired the congress, and also led the party in its early years.

The party was specifically linked to the liberated Reformed Church. Membership of the church was a pre-requisite for membership of the party. This dogmatic position isolated the party.

The party participated, without success in the 1948, 1952 and 1956 general elections. After the 1956 elections, the number of seats in parliament was extended; therefore, the number of votes needed to obtain a seat was decreased from one percent of vote to two-thirds of one percent of vote. In the 1959 general election it appeared that the GPV had won a seat. Its sole MP, Laning, was asked to visit the queen to advise her on the formation of a new cabinet. After the results were calculated exactly, however, it became clear that the GPV had obtained too few votes for a seat.

In 1963 the party finally entered the House of Representatives in the person of Pieter Jongeling, who was made top candidate on advice of prominent professor of theology J. Kamphuis. In the 1967 general elections, they were able to retain their one seat. During the early 1970s, a group called Nationaal Evanglisch Verbond (NEV) had left the ARP because they thought the party's alliance with the Catholic People's Party was wrong. They asked the board of the GPV whether they could join their party. This was rejected by the board of the GPV, who said that the party was open only to members of the liberated Reformed Church. This group would later become the Reformatory Political Federation (RPF). In the 1971 general election, the party was able to obtain a second seat, which it managed to retain in 1972. In the 1977 general election, Jongeling was replaced by Verbrugh and the party lost one seat. Before the 1981 general election, Verbrugh was replaced by Schutte, who would lead the party until 2001. He was able to retain the one seat in 1981, 1982 and 1986 general elections, and he won a second seat in 1989. In the 1994 general election the party retained its two seats. In 1993 the GPV officially opened itself to non-liberated members. This started a slow process of cooperation between the GPV and the RPF, another orthodox Protestant party. From the 1998 general election onwards, the two parliamentary parties began to cooperate, holding common meanings and appointing common spokespersons. The fact that the GPV had only two seats and the RPF three inhibited the cooperation. In 1999, their parliamentary parties in the Senate officially merged, forming one parliamentary party. In 2001, the same happened in the House of Representatives. In 2002 general election the GPV and RPF presented a common electoral list of candidates for the House of Representatives, entering the elections as the Christian Union: they obtained four seats. In 2003, the GPV officially disbanded, making its merger into the Christian Union final.

The GPV chose the name Gereformeerd Politiek Verbond (Reformed Political Alliance), because it wanted to convey that it was a reformed party, and that its organisation was decentralised: the GPV was primarily an alliance of local branches.

In its first years, the GPV did not have a separate election manifesto or manifesto of principles. Instead it claimed to base its policy directly on the bible. In 1967, the first manifesto of principles was published, in which the party again stressed that the Bible was the basis of their policy. The party saw the Netherlands as a Protestant nation, which should be defended.