The Priest Barracks of Dachau Concentration (in German Pfarrerblock, or Priesterblock) incarcerated clergy who had opposed the Nazi regime of Adolf Hitler. From December 1940, Berlin ordered the transfer of clerical prisoners held at other camps, and Dachau became the centre for imprisonment of clergymen. Of a total of 2,720 clerics recorded as imprisoned at Dachau some 2,579 (or 94.88%) were Roman Catholics. Among the other denominations, there were 109 Protestants, 22 Orthodox, 8 Old Catholics and Mariavites and 2 Muslims. Members of the Catholic Society of Jesus were the largest group among the incarcerated clergy at Dachau.

Dachau was established in March 1933 as the first Nazi Concentration Camp. Dachau was chiefly a political camp, rather than an extermination camp, but of around 160,000 prisoners sent to its main camp, over 32,000 were either executed or died of disease, malnutrition or brutalization. The prisoners of Dachau were used as guinea pigs in Nazi medical experiments. The sick were sent to Hartheim to be murdered, (framed as "euthanasia" in the T4 Program).

Along with priests, other political prisoners including Social Democrats and Communists, Jews, Gypsies, Jehovah's Witnesses and homosexuals were also incarcerated at Dachau.

Prior to the Reichstag vote for the Enabling Act under which Hitler gained the "temporary" dictatorial powers with which he went on to permanently dismantle the Weimar Republic, Hitler promised the Reichstag on 23 March 1933, that he would not interfere with the rights of the churches. However, with power secured in Germany, Hitler quickly broke this promise. He divided the Lutheran Church (Germany's main Protestant denomination) and instigated a brutal persecution of the Jehovah's Witnesses. He dishonoured a Concordat signed with the Vatican and permitted a persecution of the Catholic Church in Germany. The long term plan was to "de-Christianise Germany after the final victory". The Nazis co-opted the term Gleichschaltung to mean conformity and subservience to the National Socialist German Workers' Party line: "there was to be no law but Hitler, and ultimately no god but Hitler". Within a short period, the Nazi government's conflict with the churches had become a source of great bitterness in Germany.

Hitler himself possessed radical instincts in relation to the continuing conflict with the Catholic and Protestant Churches in Germany. Though he occasionally spoke of wanting to delay the Church struggle and was prepared to restrain his anti-clericalism out of political considerations, his "own inflammatory comments gave his immediate underlings all the license they needed to turn up the heat in the 'Church Struggle, confident that they were 'working towards the Fuhrer'". A threatening, though initially mainly sporadic persecution of the Catholic Church in Germany followed the Nazi takeover. The regime agreed the Reichskonkordat Treaty with the Vatican, which prohibited clergy from participating in politics. The Concordat, wrote William Shirer, "was hardly put to paper before it was being broken by the Nazi Government". On 25 July, the Nazis promulgated their sterilization law, an offensive policy in the eyes of the Catholic Church. Five days later, moves began to dissolve the Catholic Youth League. Clergy, nuns and lay leaders began to be targeted, leading to thousands of arrests over the ensuing years, often on trumped up charges of currency smuggling or "immorality". In the face of this persecution, Pope Pius XI issued his Mit brennender Sorge Encyclical, which denounced the pagan ideology of Nazism. In response, hundreds more clergy were arrested and sent to the concentration camps.

Ian Kershaw wrote that the subjugation of the Protestant churches proved more difficult than Hitler had envisaged. With 28 separate regional churches, his bid to create a unified Reich Church through Gleichschaltung ultimately failed, and Hitler became disinterested in supporting the so-called "German Christians" Nazi aligned movement. Hitler installed his friend Ludwig Muller, a Nazi and former naval chaplain, to serve as Reich Bishop, but Muller's heretical views against St Paul and the Semitic origins of Christ and the Bible quickly alienated sections of the Protestant church. Pastor Martin Niemöller responded with the Pastors Emergency League which re-affirmed the Bible. The movement grew into the Confessing Church, from which some clergymen opposed the Nazi regime. The Confessing Church was banned on 1 July 1937. Niemöller was arrested by the Gestapo, and sent to the Concentration Camps. He remained mainly at Dachau until the fall of the regime. Theological universities were closed, and other pastors and theologians arrested. Dietrich Bonhoeffer, another leading spokesman for the Confessing Church, was from the outset a critic of the Hitler regime's racism and became active in the German Resistance – calling for Christians to speak out against Nazi atrocities. Arrested in 1943, he was implicated in the 1944 July Plot to assassinate Hitler and executed.

In an effort to counter the strength and influence of spiritual resistance, Nazi records reveal that the security services monitored the activities of the bishops very closely – instructing that agents be set up in every diocese, that the bishops' reports to the Vatican should be obtained and that the bishops' areas of activity must be found out. Deans were to be targeted as the "eyes and ears of the bishops" and a "vast network" established to monitor the activities of ordinary clergy: "The importance of this enemy is such that inspectors of security police and of the security service will make this group of people and the questions discussed by them their special concern".

In Dachau: The Official History 1933–1945, Paul Berben wrote that clergy were watched closely, and frequently denounced, arrested and sent to concentration camps: "One priest was imprisoned in Dachau for having stated that there were good folk in England too; another suffered the same fate for warning a girl who wanted to marry an S.S. man after abjuring the Catholic faith; yet another because he conducted a service for a deceased communist". Other were arrested simply on the basis of being "suspected of activities hostile to the State" or that there was reason to "suppose that his dealings might harm society".