Hans Christian Asmussen (born 21 August 1898 in Flensburg — died 30 December 1968 in Speyer) was a German Evangelical and Lutheran theologian.

Asmussen was a pastor in Altona, Hamburg. He was removed from office by the Nazis because of his activity in the Reich Fraternal Council of the Confessing Church. He was jailed several times before 1945. He was co-author of the protest "Word and Affirmation of Altona Pastors amid the Misery and Confusion of Public Life" (11 January 1933), which rejected a pact with National Socialism and thus became a preliminary step toward the theological declaration of the Barmen Confessional Synod. From 1945 to 1948, Asmussen presided over the Evangelical Church Chancellery, and from 1949 to 1955, he was dean (German: Propst) in Kiel; he was a promoter of ecumenical dialogue. His writings include Seelsorge (Pastoral Care; 1934) and Der Römerbrief (Letter to the Romans; 1952).

Asmussen, the son of a headmaster, Jes Georg Asmussen, attended high school in Flensburg. His family came from a conservative, pious roots and was influenced greatly by Pastor Emil Wacker, a charismatic revival pastor. While in high school, he studied military combat in the tactics of the First World War until 1917. It was then his eldest brother was killed in the war, and he enlisted in the army. After serving until the war's end, he went on to study Protestant theology at the University of Kiel and University of Tübingen. While at Keil he, and a number of students, formed the "League of Lutheran Brethren" in opposition to the rising popularity of liberal theology. While at Tübingen the group was known as "the archconservatives from Flensburg".

In 1921, he became vicar and later curate at the Deaconess House in Flensburg. In 1925, he took a pastorate in Albersdorf (Dithmarschen), from where he later moved in 1932 to the pastorate of the Church of St. Trinitatis in Altona. While at Albers, he worked to reform the local church to bring in a greater portion of the populace. The conservative local populace found his views appealing, as they shared a mutual distaste in the Weimar Republic. The local populace was insistent in its refusal to fly the flag of the Weimar Republic, and thus Asmussen's choice to fly old Imperial flags gained him considerable rapport.

After the Altona Bloody Sunday incident on July 17, 1932 where eighteen people were killed in street fighting between the Sturmabteilung (SA) and Schutzstaffel (SS), the Prussian police, and Communist Party (KPD) Asmussen attempted to calm tempers by holding the funerals and stressing that vengeance was not the solution. However Hitler declared that the Nazi dead were "Christian martyrs", released a pamphlet titled Wöhrden's Bloody Night and Its Consequence and used the incident to spark more demonstrations. Asmussen wrote letters to the Nazi party and Hitler himself first begging for them to end the violence, later denouncing their action.

Asmussen was one of the main authors of a piece published on January 11, 1933 from Altona pastors stressing their concern with the affairs of Germany, which became known as the Altona Confession in the story. It denounced Hitler's use of the event for political gain and stated that the Church was not sided with the National Socialists, nor did it side with the Communists. It declared that no political party could claim to be ruled by the word of God. Its mission was also to bring both sides to peace and resolve their conflicts without violence. This declaration is considered a harbinger of the later and more famous Barmen Theological Declaration.

Hitler soon rose to power and intended to consolidate the German clergy into a single Church that supported the Nazi party. He established the German Christians, a group of pro-Nazi clergy who had government backing. After the victory of the German Christians in the church elections of 1933 in the Schleswig-Holstein church, Asmussen, as its avowed opponent, was suspended and sent into early retirement in 1934. Asmussen moved to Berlin and took over leading functions in September 1933 of the Pastors out Confessing Church. He belonged to the Reich Fraternal Council, and along with Karl Barth and Thomas Broad, drafted the Barmen Declaration and presented it at the first Barmer Confessional Synod of 1934 as the introduction speech.

In 1935 Asmussen founded, and was the director for, the Church University of Berlin-Dahlem which was opened on 1 November 1935 where he taught Practical Theology. However, in 1937 Heinrich Himmler decreed any training and tutelage of young theologians was prohibited for non-party clergy. Asmussen was a signatory of the Evangelical Church memorandum in the spring of 1936 and held a memorial service on 19 February 1937 at the Sachsenhausen concentration camp for the murdered chief legal advisor to the Provisional church leadership, Friedrich Weissler. In 1939, a wide-ranging speech and sermon ban was imposed on Asmussen and other non-state clergy, who were on the lists of BK for the persecuted Christians.