The Temporary Military Railway Office (Japanese: 臨時軍用鐵道幹部, Rinji Gun'yō Tetsudōkanbu; Korean: 임시 군용 철도감부, Imsi Gunyong Cheoldoganbu), was a pseudo-corporate entity established by the Imperial Japanese Army to build and operate the Gyeongui Line railway from Gyeongseong (today: Seoul) to Sinuiju.

Construction of a railway line running north from Hanseong had been envisioned since the end of the 19th century, but the lack of funding led to the failure of several attempts.

[2] Imperial Japan, which had gained the concession to build the Gyeongbu Line from Seoul to Busan, recognising that a railway running through all of Korea from north to south would serve as a means to strengthen its influence over Korea, sought to gain control of the Gyeongui Line project as well.

[1] When the Russo-Japanese War broke out in 1904, Japan ignored Korea's declaration of neutrality, transporting troops to Incheon and forcing the Korean government to sign an agreement that gave Japan's military control of railway projects if deemed necessary for military operations.

In the following year, bridges were completed over the Cheongcheon and Daedong rivers, allowing for the operation of through trains between Yongsan and Sinŭiju.