Federal elections were held in Switzerland on 20 October 2019 to elect all members of both houses of the Federal Assembly. This was followed by the 2019 election to the Swiss Federal Council, the federal executive, by the United Federal Assembly.

In the 20 October elections, the two green parties, the Green Party of Switzerland and the Green Liberal Party of Switzerland, made major electoral gains, taking 13.2% and 7.8% of the vote respectively. As in the previous election, the Swiss People's Party received the most votes, but its share of votes went down to 25.6% from 29.4%.

Initial media coverage interprets the 2019 election results as a "green wave" marking a leftward shift of the Swiss electorate on the political spectrum. It remains to be seen what effect the changes in the relative vote and seat shares will have on the composition of the Federal Council, or at least on the government's agenda and legislative initiatives, if there is no change in party representation in the executive branch.

In contrast to Germany and Austria, the Swiss federal government has for decades been composed of representatives of the four largest parties as a matter of political practice (rather than constitutional design); it has long operated on a consensus-seeking model characterised by accommodation of competing interests and viewpoints, rather than imposition of the will of the majority over the opposition.

Switzerland's confederate structure and frequent initiatives and referendums pose additional constraints on what elected politicians are collectively able to accomplish. For these reasons, the strong electoral gains of the two green parties do not have the same implications for coalition-government formation as they do in Austria following the 29 September 2019 parliamentary elections there, in which the Greens obtained their best results ever with 13.9% of the vote and 26 seats in a slightly smaller lower house of Parliament.

The elections for the National Council took place nationally on 20 October 2019.

The cantons individually organise their elections for the Council of States, which all held on 20 October 2019, with one exception. In Appenzell Innerrhoden the election took place on 28 April at the 2019 Landsgemeinde. Depending on the results of the 20 October election, a second round or runoff election may be required in some cantons.

The 200 members of the National Council are elected from 26 cantons, each of which constitutes a constituency. The cantons are of unequal population size and use different electoral systems. Six are single-member constituencies in which winners are determined by first-past-the-post voting; the remaining 20 cantons are multi-member constituencies, in which members are elected by open list proportional representation. Voters may cross out names on party lists, split their vote between parties (a system known as panachage), or draw up their own list on a blank ballot. Seats are allocated using the Hagenbach-Bischoff system.