Catholicism reached the Cheongju region before the Shin-yu Persecution of 1801 (신유박해, 1801), yet most believers were forced to practice their faith in hiding. After a degree of freedom for missionary activity was granted in 1882, small communities quickly formed, and the number of faithful increased steadily.

In 1896, Fr. Buyiong (Louis Beille, MEP) built a church in Gamgok 감곡(甘谷),establishing the region’s first official parish. A second parish followed in Okcheon 옥천(沃川) in 1906, and additional parishes were founded in Cheongju 청주, Jeungpyeong증평, Jecheon 제천, and Gyoheon교현. However, the Jeungpyeong parish closed during the Korean War, leaving five parishes to be entrusted in 1953 to the Maryknoll Foreign Mission Society as the Apostolic Prefecture of Chungcheongbuk-do.

On June 23, 1958, the Apostolic Prefecture was elevated to the Apostolic Vicariate of Cheongju 청주대목구,and Fr. James Pardy, MM (파디 야고보) was appointed the first Vicar Apostolic on July4. He received episcopal consecration in the United States on September 16 and was ordained bishop on November 26 of the same year. With the establishment of the Korean ecclesiastical hierarchy in 1962, Cheongju was elevated to the rank of a diocese.

A major turning point came on June 3, 1999, when Fr. Jang Bong-hun 장봉훈 was appointed the third Bishop of Cheongju and was ordained and installed on August 24 at Naedeok 2-dongCathedral.

Over the past fifty years, the Diocese of Cheongju has undergone significant transformation. In the late 1950s, Korean society suffered from severe economic hardship and political instability. During this period, the Maryknoll missionaries and local Catholic communities planted the seeds for evangelization through their spiritual dedication and missionary commitment.

At the time of its establishment in 1958, the diocese consisted of 15 parishes, approximately 21,000 faithful, and 25Maryknoll priests. As of May 2016, it has grown remarkably, with 76 parishes(including two quasi-parishes), around 163,000 faithful, 183 priests, and numerous institutions, including middle and high schools, a special-needs school, a general hospital, and over sixty social welfare facilities.

With its diocesan synod, Cheongju began a new journey toward its centennial, setting forth Vision 2050—looking ahead to the year 2020 and beyond, aiming for 200,000 faithful and 100parishes. This vision is not merely a call for numerical growth but an invitation to renewal, progress, and a renewed commitment to fulfilling the Church’s mission as a sign of light and hope within society and the world.