The Swiss Brethren (German: Schweizer Brüder) are a branch of Anabaptism that started in Zürich, spread to nearby cities and towns, and then was exported to neighboring countries. Today's Swiss Mennonite Conference can be traced to the Swiss Brethren.

In 1525, Felix Manz, Conrad Grebel, George Blaurock and other radical evangelical reformers broke from Ulrich Zwingli and formed a new group because they felt reforms were not moving fast enough.

Rejection of infant baptism was a distinguishing belief of the Swiss Brethren. On the basis of Sola scriptura doctrine, the Swiss Brethren declared that since the Bible does not explicitly mention infant baptism, it should not be practiced by the church. This belief was subsequently rejected by Ulrich Zwingli. Consequently, there was a public dispute, in which the council affirmed Zwingli's position. This solidified the Swiss Brethren and resulted in their persecution by all other reformers as well as the Catholic Church.

Because of persecution by the authorities, many Swiss Brethren moved from Switzerland to neighboring countries. The Swiss Brethren became known as Mennonites after the division of 1693, a disagreement between groups led by Jakob Ammann and Hans Reist. Many of the Mennonites in France, Southern Germany, the Netherlands, and North America, as well as most Amish, descend from the Swiss Brethren.

In 1527 Michael Sattler authored the Schleitheim Articles, the first Anabaptist confession of faith. It contained seven articles on the following topics:

Most Swiss Brethren accepted these seven articles.

George Blaurock (Bonaduz, c. 1491 – 1529) was a co-founder of the Swiss Brethren movement. He was educated at the University of Leipzig and served as a priest, but departed from the Catholic Church before he arrived in Zürich around 1524, for he had already taken a wife. Though he came to see Huldrych Zwingli, he soon became attached to the reformer's more radical followers. After a break with Zwingli in January 1525 and acting against a Zürich city council ruling, Blaurock asked Conrad Grebel to baptize him upon a confession of faith in Christ. Grebel did so, and afterwards Blaurock proceeded to baptize the others who were present. Blaurock worked closely with Felix Manz until Manz was martyred in Zürich in 1527. On that same day, Blaurock was severely beaten and permanently expelled from Zürich. He kept moving, laboring at Bern, Biel, the Grisons, and Appenzell. After his arrest and fourth banishment in 1527, Blaurock left Switzerland never to return. He conducted a very successful ministry in Tyrol. In August 1529 he was arrested by Innsbruck authorities and tortured for information. On 6 September 1529, Blaurock was burned at the stake near Klausen.

Conrad Grebel (c. 1498 – 1526) was a co-founder of the Swiss Brethren movement. He was probably born in Grüningen about 1498. His family moved to Zürich around 1513. Grebel spent about six years in three universities, but without finishing his education or receiving a degree. In 1521 he joined a group gathered around Zürich reformer Huldrych Zwingli to study the Greek classics, the Latin Bible, the Hebrew Old Testament and the Greek New Testament. Core members of the group broke with Zwingli because they thought the reform process was proceeding too slowly. At a gathering in January 1525 George Blaurock asked Grebel to baptize him upon a confession of faith. Afterward, Blaurock baptized Grebel and the others, initiating a wave of rebaptisms that would spread throughout the Swiss cantons. Grebel died of the plague in 1526.