This is a list of formations of the United States Army during the World War II. Many of these formations still exist today, though many by different designations. Included are formations that were placed on rolls, but never organized, as well as "phantom" formations used in the Allied Operation Quicksilver deception of 1944—these are marked accordingly.

Army groups

1st Army Group ("phantom" formation) 6th Army Group 12th Army Group 15th Army Group

List of formations of the United States Army during World War II

Field armies

First Allied Airborne Army

First United States Army

Second United States Army

Third United States Army

Fourth United States Army

Fifth United States Army

Sixth United States Army

Seventh United States Army

Eighth United States Army

Ninth United States Army

Tenth United States Army

Fourteenth United States Army ("phantom" formation) Fifteenth United States Army

List of formations of the United States Army during World War II

Corps

I Corps

I Armored Corps

II Corps

III Corps

IV Corps

V Corps

VI Corps

VII Corps

VIII Corps

IX Corps

X Corps

XI Corps

XII Corps

XIII Corps

XIV Corps

XV Corps

XVI Corps

XVIII Airborne Corps

XIX Corps

XX Corps

XXI Corps

XXII Corps

XXIII Corps

XXIV Corps

XXXIII Corps ("phantom" formation) XXXVI Corps XXXVII Corps ("phantom" formation)

List of formations of the United States Army during World War II

Divisions

Airborne, armored, cavalry, infantry, and mountain divisions are grouped separately. The numbering system for the airborne and mountain divisions are a continuation of the infantry numbering system—"phantom" formations are an exception to that numbering system.

Airborne divisions

6th Airborne Division ("phantom" formation) 9th Airborne Division ("phantom" formation) 11th Airborne Division 13th Airborne Division 15th Airborne Division (unorganized) 17th Airborne Division 18th Airborne Division ("phantom" formation) 21st Airborne Division ("phantom" formation) 82nd Airborne Division 101st Airborne Division 135th Airborne Division ("phantom" formation)

Armored divisions

1st Armored Division

2nd Armored Division

3rd Armored Division

4th Armored Division

5th Armored Division

6th Armored Division

7th Armored Division

8th Armored Division

9th Armored Division

10th Armored Division

11th Armored Division

12th Armored Division

13th Armored Division

14th Armored Division

15th Armored Division ("phantom" formation) 16th Armored Division 18th Armored Division (constituted but never activated) 19th Armored Division (constituted but never activated) 20th Armored Division 21st Armored Division (constituted but never activated) 22nd Armored Division (constituted but never activated) 25th Armored Division ("phantom" formation) 39th Armored Division ("phantom" formation)