| Unit Name: | 1st Mobile Fleet |
| Dates: | 1 March 1943 - 15 November 1944 |
| Battle Honours: | Pacific Theatre of World War II |
The was a fleet of the Imperial Japanese Navy established during World War II.
| Date | Higher Fleet | Lower Fleets | Divisions, Squadrons and attached elements | |
|---|---|---|---|---|
| 1 March 1944 (original) | 4th CruDiv., 5th CruDiv., 2nd CruDesron. | |||
| 1st CarDiv., 2nd CarDiv., 3rd BatDiv., 7th CruDiv., 10th CruDesron., Aircraft carrier Chitose, Heavy cruiser Mogami, Light cruiser Ōyodo, 601st NAG | ||||
| 1 April 1944 | 2nd Fleet | 4th CruDiv., 5th CruDiv., 7th CruDiv., 2nd CruDesron. | ||
| 3rd Fleet | 1st CarDiv., 2nd CarDiv., 3rd CarDiv., 3rd BatDiv., 10th CruDesron., Heavy cruiser Mogami, 601st NAG | |||
| 1 May 1944 | 2nd Fleet | 4th CruDiv., 5th CruDiv., 7th CruDiv., 2nd CruDesron. | ||
| 3rd Fleet | 1st CarDiv., 2nd CarDiv., 3rd CarDiv., 4th CarDiv., 3rd BatDiv., 10th CruDesron., Heavy cruiser Mogami, 601st NAG | |||
| 10 July 1944 | 2nd Fleet | 1st BatDiv., 4th CruDiv., 5th CruDiv., 7th CruDiv., 2nd CruDesron. | ||
| 3rd Fleet | 1st CarDiv., 3rd CarDiv., 4th CarDiv., 3rd BatDiv., 10th CruDesron., Heavy cruiser Mogami, 601st NAG | |||
| 15 August 1944 | 2nd Fleet | 1st BatDiv., 3rd BatDiv., 4th CruDiv., 5th CruDiv., 7th CruDiv., 2nd CruDesron. | ||
| 3rd Fleet | 1st CarDiv., 3rd CarDiv., 4th CarDiv., 10th CruDesron., Heavy cruiser Mogami, 601st NAG | |||
| 15 October 1944 | 2nd Fleet | 1st BatDiv., 2nd BatDiv., 3rd BatDiv., 4th CruDiv., 5th CruDiv., 7th CruDiv., 2nd CruDesron. | ||
| 3rd Fleet | 1st CarDiv., 3rd CarDiv., 4th CarDiv., 10th CruDesron., Heavy cruiser Mogami, 601st NAG | |||
| 7th Subron., 8th Subron., 11th Subron., 15th Subflotilla, 34th Subflotilla, Submarine I-12, 22nd CruDiv., 11th CruDesron., 31st CruDesron., Aircraft carrier Hōshō, Seaplane tender Akitsushima, Auxiliary submarine tender Tsukushi Maru, No.30 Submarine Base Unit, No.31 Submarine Base Unit | ||||
| 15 November 1944 | disbanded | |||
Commander in chief
| Rank | Name | Date | Additional post | |
| 1 | Vice-Admiral | Jisaburō Ozawa | 1 March 1944 | Commander of the 3rd Fleet and the 1st Carrier Division |
| 1 October 1944 | Commander of the 3rd Fleet (and direct control for the 3rd Carrier Division) | |||
Chief of staff
| Rank | Name | Date | Additional post | |
| 1 | Rear-Admiral | Keizō Komura | 1 March 1944 | Chief of staff of the 3rd Fleet |
| 2 | Rear-Admiral | Sueo Ōbayashi | 1 October 1944 | Chief of staff of the 3rd Fleet |