The Swiss People's Party (German: Schweizerische Volkspartei, SVP; Romansh: Partida populara Svizra, PPS), also known as the Democratic Union of the Centre (French: Union démocratique du centre, UDC; Italian: Unione Democratica di Centro, UDC), is a national-conservative and right-wing populist political party in Switzerland. Chaired by Marcel Dettling, it is the largest party in the Federal Assembly, with 62 members of the National Council and 6 of the Council of States.

The SVP originated in 1971 as a merger of the Party of Farmers, Traders and Independents (BGB) and the Democratic Party, while the BGB, in turn, had been founded in the context of the emerging local farmers' parties in the late 1910s. The SVP initially did not enjoy any increased support beyond that of the BGB, retaining around 11% of the vote through the 1970s and 1980s. This changed however during the 1990s, when the party underwent deep structural and ideological changes under the influence of Christoph Blocher; the SVP then became the strongest party in Switzerland by the 2000s.

In line with the changes fostered by Blocher, the party started to focus increasingly on issues such as Euroscepticism and opposition to mass immigration. Its vote share of 28.9% in the 2007 federal election was the highest vote ever recorded for a single party in Switzerland until 2015, when it surpassed its own record with 29.4%. Blocher's failure to win re-election as a Federal Councillor led to moderates within the party splitting to form the Conservative Democratic Party (BDP), which later merged with the Christian Democratic People's Party into The Centre. As of 2024^[update], the party is the largest in the National Council with 62 seats. It has six seats in the Council of States.

The early origins of the SVP go back to the late 1910s, when numerous cantonal farmers' parties were founded in agrarian, Protestant, German-speaking parts of Switzerland. While the Free Democratic Party had earlier been a popular party for farmers, this changed during World War I when the party had mainly defended the interests of industrialists and consumer circles. When proportional representation was introduced in 1919, the new farmers' parties won significant electoral support, especially in Zürich and Bern, and eventually also gained representation in parliament and government. By 1929, the coalition of farmers' parties had gained enough influence to get one of their leaders, Rudolf Minger, elected to the Federal Council.

In 1936, a representative party was founded on the national level, called the Party of Farmers, Traders and Independents (BGB). During the 1930s, the BGB entered the mainstream of Swiss politics as a right-wing conservative party in the bourgeois bloc. While the party opposed any kind of socialist ideas such as internationalism and anti-militarism, it sought to represent local Swiss traders and farmers against big business and international capital.

The BGB contributed strongly to the establishment of the Swiss national ideology known as the Geistige Landesverteidigung (Spiritual Defence of the Nation), which was largely responsible for the growing Swiss sociocultural and political cohesion from the 1930s. In the party's fight against left-wing ideologies, sections of party officials and farmers voiced sympathy with, or failed to distance themselves from, emerging fascist movements. After World War II, the BGB contributed to the establishment of the characteristic Swiss post-war consensual politics, social agreements and economic growth policies. The party continued to be a reliable political partner with the Swiss Conservative People's Party and the Free Democratic Party.

In 1971, the BGB changed its name to the Swiss People's Party (SVP) after it merged with the Democratic Party from Glarus and Grisons. The Democratic Party had been supported particularly by workers, and the SVP sought to expand its electoral base towards these, as the traditional BGB base in the rural population had started to lose its importance in the post-war era. As the Democratic Party had represented centrist, social-liberal positions, the course of the SVP shifted towards the political centre following internal debates. The new party however continued to see its level of support at around 11%, the same as the former BGB throughout the post-war era. Internal debates continued, and the 1980s saw growing conflicts between the Bern and Zürich cantonal branches, where the former branch represented the centrist faction, and the latter looked to put new issues on the political agenda.

When the young entrepreneur Christoph Blocher was elected president of the Zürich SVP in 1977, he declared his intent to oversee significant change in the political line of the Zürich SVP, bringing an end to debates that aimed to open the party up to a wide array of opinions. Blocher soon consolidated his power in Zürich, and began to renew the organisational structures, activities, campaigning style and political agenda of the local branch. The young members of the party was boosted with the establishment of a cantonal Young SVP (JSVP) in 1977, as well as political training courses. The ideology of the Zürich branch was also reinforced, and the rhetoric hardened, which resulted in the best election result for the Zürich branch in fifty years in the 1979 federal election, with an increase from 11.3% to 14.5%. This was contrasted with the stable level in the other cantons, although the support also stagnated in Zürich through the 1980s.