The concept of universal franchise, also known as general suffrage or common suffrage, consists of the right to vote of all adult citizens, regardless of wealth, income, gender, social status, race, or ethnicity, subject only to minor exceptions.^[8][9] In its original 19th-century usage by political reformers, universal suffrage was understood to mean only universal manhood suffrage; the vote was extended to women later, during the women's suffrage movement.^[10][11]

There are variations among countries in terms of specifics of the right to vote; the minimum age is usually between 18 and 25 years (see age of majority) and "the insane, certain classes of convicted criminals, and those punished for certain electoral offenses" sometimes lack the right to vote.^[9]

In most countries, universal suffrage (the right to vote but not necessarily the right to be a candidate) followed about a generation after universal adult franchise. Notable exceptions in Europe were France, where women could not vote until 1944, Greece (1952), and Switzerland (1971).

In the first modern democracies, governments restricted the vote to those with property and wealth, which almost always meant a minority of the male population. In some jurisdictions, other restrictions existed, such as requiring voters to practice a given religion. In all modern democracies, the number of people who could vote has increased progressively with time. In the 19th century in Europe, Great Britain and North America, there were movements advocating "universal [male] suffrage".

In the United States, "universal suffrage" is often associated with "one man, one vote" which was achieved during 1960s after a series of landmark decisions from the U.S. Supreme Court under Chief Justice Earl Warren.^[12][13][14] In addition, the term "suffrage" is also associated specifically with women's suffrage, a movement to extend the franchise to women began in the mid-nineteenth century and culminated in 1920, when the United States ratified the Nineteenth Amendment to the United States Constitution, guaranteeing the right of women to vote.

France, under the 1793 Jacobin constitution, was the first major country to enact suffrage for all adult males, though it was never formally used in practice (the subsequent election occurring in 1795 after the fall of the Jacobin government in 1794). Elsewhere in the Francophone world, the Republic of Haiti legislated for universal male suffrage in 1816.^[15] The Second French Republic instituted adult male suffrage after the revolution of 1848.

Following the French revolutions, movements in the Western world toward universal suffrage occurred in the early 19th century, and focused on removing property requirements for voting. In 1867 Germany (the North German Confederation) enacted suffrage for all adult males. In the United States following the American Civil War, slaves were freed and granted rights of citizens, including suffrage for adult males (although several states established restrictions largely, though not completely, diminishing these rights). In the late-19th and early-20th centuries, the focus of the universal suffrage movement came to include the extension of the right to vote to women, as happened from the post-Civil War era in several Western states and during the 1890s in a number of British colonies.

On 19 September 1893 the Governor of New Zealand, Lord Glasgow, signed a new Electoral Act into law. As a result of this landmark legislation, New Zealand became the first self-governing country in the world in which women had the right to vote in parliamentary elections.^[16] In 1906, the autonomous Grand Duchy of Finland (which became the Republic of Finland in 1917) became the first country in the world to implement full universal suffrage, as women could stand as candidates, unlike in New Zealand, and ethnic exclusion was not implemented, unlike in Australia. It also elected the world's first female members of parliament the following year.^[17][18]

The First French Republic was the second nation that adopted universal male suffrage, doing so in 1792; it was one of the first national systems that abolished all property requirements as a prerequisite for allowing men to register and vote. Greece recognized full male suffrage in 1830. Spain recognized it in the Constitution of 1869 and France and Switzerland have continuously done so since the 1848 Revolution (for resident male citizens). Upon independence in the 19th century, several Latin-American countries and Liberia in Africa initially extended suffrage to all adult males, but subsequently restricted it based on property requirements. The German Empire implemented full male suffrage in 1871.

In the United States, the Fifteenth Amendment to the United States Constitution, ratified in 1870 during the Reconstruction era, provided that "The right of citizens of the United States to vote shall not be denied or abridged by the United States or by any State on account of race, color, or previous condition of servitude." This amendment aimed to guarantee the right to vote to African Americans, many of whom had been enslaved in the South prior to the end (1865) of the American Civil War and the 1864-1865 abolition of slavery. Despite the amendment, however, blacks were disfranchised in the former Confederate states after 1877; Southern officials ignored the amendment and blocked black citizens from voting through a variety of devices, including poll taxes, literacy tests, and grandfather clauses;^[19] violence and terrorism were used to intimidate some would-be voters.^[20] Southern blacks did not effectively receive the right to vote until the Voting Rights Act of 1965.^[19]

In 1893 the self-governing colony New Zealand became the first country in the world (except for the short-lived 18th-century Corsican Republic) to grant active universal suffrage by giving women the right to vote. It did not grant universal full suffrage (the right to both vote and be a candidate, or both active and passive suffrage) until 1919.^[21]

In 1902 the Commonwealth of Australia become the first country to grant full suffrage for women, i.e. the first country in the world to give women the rights both to vote and to run for office.^[22] However, Australia did not implement universal suffrage at this time - Aboriginal Australians did not get the right to vote until 1962, because in the early 20th century Australian law did not considered them human.

Several European nations that had enacted universal suffrage had their normal legal process, or their status as independent nations, interrupted during and after the First World War of 1914-1918.

Many societies in the past have denied or abridged political representation on the basis of race or ethnicity, related to discriminatory ideas about citizenship. For example, in apartheid-era South Africa, non-white people could generally not vote in national elections until the first multi-party elections in 1994 (except under the Cape Qualified Franchise, which was replaced by a number of separate MPs in 1936 (Blacks) and 1958 (Coloureds), later by the Tricameral Parliament). Rhodesia enacted a similar statute in its proclaimed independence of 1965, which however allowed a smaller number of representatives for the considerably larger Black majority (under its 1961 constitution, the voting classes had been based on socio-economic standards, which marginalized most Black and a few White voters to a separate set of constituencies, under the principle of weighted voting; this was replaced in 1969 by an openly racial franchise, with delegated all Blacks to the 'B' voters roll).

Some nations, notably most of the United States and the United Kingdom, disenfranchise based on criminal convictions. All US states, with the exceptions of Maine and Vermont, disfranchise some felons from voting depending on their current incarceration, parole or probation status; a number of US states permanently disfranchise some felons, even after their release from prison.^[23] Many states within the U.S. previously disfranchised paupers, persons who either paid no direct taxes, or received public assistance.^[24]

Nations have differing degrees of legal recognition of non-resident citizens: non-resident Danes cannot vote after two years;^[25] non-resident Italians may vote for representatives at-large in the Italian parliament; non-resident British citizens cannot vote for their national parliament unless they have lived in the UK within the last fifteen years.^[26] A few nations also restrict those who are part of the military or police forces, e.g. Kuwait.^[27]

Many democratic countries, for example the United Kingdom and France, have had colonies with citizens living outside of the mother country and have generally not been entitled to vote for the national legislature. A peculiarly complex case is that of Algeria under the Third French Republic: Algeria was legally an integral part of France, but citizenship was restricted (as in other French colonies proper) by legal status, not by race or ethnicity. Any Muslim Algerian could become a French citizen by choosing to live like one. As this required the person to resign jurisdiction under Islamic law in favour of French civic law, very few did. Among Muslims, such a change was considered apostasy from Islam, which was the dominant religion in Algeria. Colonists in America declared Independence from Great Britain citing "No Taxation Without Representation" as one of their main grievances. However, the newly established country did not extend voting rights in the United States beyond white adult male property owners (about 6% of the population),^[28] and did not grant its overseas citizens the right to vote in elections either, until the passage of the Uniformed and Overseas Citizens Absentee Voting Act in 1986.

Citizens of an EU Member State are allowed to vote in EU parliamentary elections, as well as some local elections. For example, a British person living in Graz, Austria, would be entitled to vote for the European Parliament as a resident of the "electoral district" of Austria, and to vote in Graz municipal elections. He would, however, not be entitled to vote in Austrian (federal) elections, or Styrian (state) elections. Similarly, all locally resident EU citizens in the UK are allowed to vote for representatives of the local council, and those resident in Scotland, Wales and Northern Ireland may vote for the devolved parliaments or assemblies. But, only British, Irish and Commonwealth citizens are allowed to vote for the British House of Commons.^[29] However, not all British citizens are allowed to vote, since non-resident British citizens lose their franchise after 15 years. In fact the British government is planning to reinstate universal suffrage soon.^[30]

States have granted and revoked universal suffrage at various times. This list can be organised in three ways:

In Sweden-Finland, women's suffrage was granted during the Age of Liberty from 1718 until 1772.^[79]

In Corsica, women's suffrage was granted in 1755 and lasted until 1769.^[80]

Women's suffrage (with the same property qualifications as for men) was granted in New Jersey in 1776 (the word "inhabitants" was used instead of "men" in the 1776 Constitution) and rescinded in 1807.

The Pitcairn Islands granted restricted women's suffrage in 1838. Various other countries and states granted restricted women's suffrage in the later half of the nineteenth century, starting with South Australia in 1861.

The first unrestricted women's suffrage in a major country was granted in New Zealand in 1893.^[21] The women's suffrage bill was adopted mere weeks before the general election of 1893. Māori men had been granted suffrage in 1867, white men in 1879. The Freedom in the World index lists New Zealand as the only free country in the world in 1893.^[80]

South Australia first granted women suffrage and allowed them to stand for parliament in 1894.

The autonomous Grand Principality of Finland, a decade before becoming the republic of Finland, was the first country in the world to implement full universal suffrage, by giving women full political rights, i.e. both the right to vote and to run for office, and was the second in the world and the first in Europe to give women the right to vote.^[17][18] The world's first female members of parliament were elected in Finland the following year, 1907.

In 1931, the Second Spanish Republic allowed women the right of passive suffrage with three women being elected.

During a discussion on extending women's right to active suffrage, the Radical Socialist Victoria Kent confronted the Radical Clara Campoamor. Kent argued that Spanish women were not yet prepared to vote and, since they were too influenced by the Catholic Church, they would vote for right-wing candidates. Campoamor however pleaded for women's rights regardless of political orientation. Her point finally prevailed and, in the election of 1933, the political right won with the vote of citizens of any sex over 23. Both Campoamor and Kent lost their seats.

The movement to lower the voting age is one aspect of the Youth rights movement. Organizations such as the National Youth Rights Association are active in the United States to advocate for a lower voting age, with some success,^[81] among other issues related to youth rights.

Democratic schools practice and support universal suffrage in school, which allows a vote to every member of the school, including students and staff. Such schools hold that this feature is essential for students to be ready to move into society at large.^[82][83]