Weighted voting are voting rules that grant some voters a greater influence than others (which contrasts with rules that assign every voter an equal vote). Such can be produced by some voters having more votes than others or by fewer voters having the same representation as another larger group of voters. It may be intentional or an unhappy byproduct of the chosen electoral system.

Examples include publicly-traded companies (which typically grant stockholders one vote for each share they own), and the European Council, where the number of votes of each member state is roughly proportional to the square root of the population, which allows an uneven ratio of voters to members.

The Roman assemblies provided for weighted voting after the person's tribal affiliation and social class (i.e. wealth). Rather than counting one vote per citizen, the assemblies convened in blocs (tribes or centuries), with the plurality of voters in each bloc deciding the vote of the bloc as an entity (which candidate to support or whether to favor or reject a law, for instance). Men of certain tribes and a higher social standing convened in smaller blocs, thus giving their individual vote the effect of many poor citizens' votes. In the Plebeian Council, where only the plebeians could participate, these effects were somewhat relaxed, thus making the decision to grant its decisions (called plebiscites) the full force of law controversial (Lex Hortensia in 287 BC).

In several Western democracies, such as Sweden and pre-unitary Germany, weighted voting preceded equal and universal suffrage, as well as women's suffrage, to different extents. In Sweden, universal and equal male suffrage to the lower house (Andra kammaren) was introduced by Arvid Lindman's first cabinet, while voting for city and county councils, which indirectly decided the composition of the upper house (Första kammaren), was graded along a 40-degree scale. Certain corporations also had votes of their own, thus multiplying the political strength of its owners. Weighted voting was abolished in Nils Eden's reforms of 1918-19, when female suffrage was also introduced.

After 1946 and the Brazzaville Conference of 1944, French colonial authorities set up a system of double collège where the local population would be divided in two electoral colleges, both returning the same numbers of delegates, the first being composed by French citizens and évolués and the second by natives with indigenous status.

This system was also used in French Algeria until 1958.

This system was abolished in 1958 with the Loi Cadre Defferre.

Under its 1961 Constitution, the British colony of Southern Rhodesia provided for a special form of weighted voting called cross-voting. Essentially, voters were rounded up in two voters' rolls, with the A roll bearing requirements generally reached by the European-descended population, but only in a few cases by Africans. The B roll provided for many Africans and a few Europeans, but not all the adult population. Despite its limited size in terms of voters, the A roll played the major influence in electing the 65 members of parliament, which was further bolstered by the lack of support to sign up for the B roll, and its much lower turnout.