The expulsion of Western missionaries from the Korean peninsula by the Japanese colonial government in the early 1940s meant that Korean Catholics quickly had to learn to govern the Catholic Church on their own in an extremely complex and fast-changing Korea. After the liberation of Korea in 1945 from Japanese colonial rule, Catholics in the southern half of Korea enjoyed freedom to practice Catholicism, but Catholics in the northern half suffered persecution under communists. The redrawing of the border at the 38th parallel in 1953 after the Korean War (1950–1953) severed the means of communication between Catholics in South and North Korea meant that Catholics in North Korea were isolated, and that the anti-religious atmosphere became even more inhospitable to Catholics. The Korean Catholic Church’s interest in anti-communism helped establish a good relationship with the Rhee administration. However, the growing interest of Catholics in social and political issues of South Korea soon created tension between Catholics and the South Korean governments. With the establishment of the Church hierarchy in Korea in 1962 and the creation of the first Korean cardinal in 1969, Korean Catholics developed their own voice for seeking human rights of workers and democracy of South Korea. This chapter explores how the history of the Catholic Church in Korea became intertwined with foreign missionaries, local Catholics, and Korean social and political contexts after Korea’s liberation in 1945.