The League of Christian Socialists (Dutch: Bond Christen-Socialisten, or BCS) was a Dutch Christian socialist political party.
The BCS was founded in 1907. In the 1918 elections, the first election with a system of proportional representation and male universal suffrage the threshold for the House of Representatives was relatively low, at just over half of 1% of the vote. Consequently the BCS was elected with only 8000 votes (that is 0.6% of vote).
In parliament the party worked together with Socialist Party and the Social Democrat Party (later Communist Party Holland) in the revolutionary parliamentary party. In 1919 the SP MP had left the parliamentary party, disaffected with the cooperation. The BCS representative however embraced the cooperation and left his own party with to join the Communist Party Holland. Some members joined him, while others joined the social-democratic SDAP, a third group continued separately and founded the Christian Democratic Union with the Christian Social Party and the Christian Democratic Party in 1926.
The BCS was both a Marxist and a Christian party. In its manifesto of principles called "God, Thyself, Thy neighbour", the BCS took the second commandment of Christ from the Gospel of Matthew, "Thou shall love thy neighbour like thyself", as its leading principle.