| Unit Name: | Western District Army |
| Dates: | August 1, 1937 – November 30, 1945 |
| Country: | Empire of Japan |
| Branch: | Imperial Japanese Army |
| Type: | Infantry |
| Role: | Field Army |
| Battles: | Operation Downfall |
The was a regional command of the Imperial Japanese Army (equivalent to a field army) responsible for the defense of the Kantō region and western Honshū, Shikoku and Kyūshū during the Pacific War. It was one of the regional commands in the Japanese home islands reporting to the General Defense Command.
The Western District Army was established on 2 August 1937 as part of the regional realignment of the Imperial Japanese Army as the . It was essentially a home guard and garrison responsible for recruitment and civil defense.
On 1 August 1940, it was renamed again as the, which became the Western District Army on 1 February 1945.
The Western District Army existed concurrently with the Japanese 16th Area Army and the Japanese 15th Area Army, which were tasked with organizing the final defenses of Kyūshū and Shikoku against the expected American invasion of the Japanese home islands. The Western District Army assumed all administrative functions, whereas the individual area armies were operational combat commands.
The Western District Army remained active for several months after the surrender of Japan to help maintain public order until the arrival of the American occupation forces, and to oversee the final demobilization and dissolution of the Imperial Japanese Army.
| Name | From | To | |
| 1 | 2 August 1937 | 15 July 1938 | |
| 2 | Lieutenant General Takuro Matsui | 15 July 1938 | 9 March 1940 |
| 3 | 9 March 1940 | 10 April 1941 | |
| 4 | General Keisuke Fujie | 10 April 1941 | 22 March 1944 |
| 5 | 22 March 1944 | 22 November 1944 | |
| 6 | Lieutenant General Isamu Yokoyama | 22 November 1944 | 13 October 1945 |
| 7 | 13 October 1945 | 30 November 1945 | |
| Name | From | To | |
| 1 | Major General Shuntoku Nagami | 2 August 1937 | 15 July 1938 |
| 2 | Major General Rion NIshimura | 15 July 1938 | 9 March 1940 |
| 3 | Lieutenant General Kazuo Isa | 9 March 1940 | 1 March 1941 |
| 4 | Lieutenant General Shinnosuke Sasa | 1 March 1941 | 22 December 1942 |
| 5 | Lieutenant General Wataro Yoshinaka | 22 December 1942 | 3 May 1945 |
| 6 | Lieutenant General Masazumi Ineda | 3 May 1945 | 13 October 1945 |