The following Union Army units and commanders fought in the Battle of Pea Ridge. The Pea Ridge Confederate order of battle is shown separately.
See main article: Army of the Southwest.
| Brigade | width=30% | Unit | width=15% | Commander | Killed | Wounded | Missing | Casualties |
|---|---|---|---|---|---|---|---|---|
| Headquarters | Not Brigaded | 24th Missouri Volunteer Infantry Companies A, B, F, H, I | Maj Eli W. Weston | 3 | 16 | 7 | 26 | |
| 3rd Regiment Iowa Volunteer Cavalry Companies A, B, C, D, M | 24 | 17 | 9 | 50 | ||||
| Maj William D. Bowen | 1 | 3 | 2 | 6 | ||||
BG Franz Sigel
| Brigade | width=30% | Unit | width=15% | Commander | Killed | Wounded | Missing | Casualties |
|---|---|---|---|---|---|---|---|---|
| First Division Col Peter J. Osterhaus | First Brigade Col Peter J. Osterhaus | Col William N. Coler | 3 | 18 | 3 | 24 | ||
| Col Charles Knobelsdorff | 1 | 2 | 0 | 3 | ||||
| 17th Missouri Volunteer Infantry, Company A detached | Maj August H. Poten | 0 | 2 | 8 | 10 | |||
| Second Brigade Col Nicholas Greusel | 36th Illinois Volunteer Infantry Regiment Company F detached | Col Nicholas Greusel | 4 | 37 | 34 | 75 | ||
| 12th Missouri Volunteer Infantry, Company E detached | Maj Hugo Wangelin | 3 | 29 | 2 | 34 | |||
| Artillery | Cpt Louis Hoffman | 1 | 4 | 0 | 5 | |||
| Welfley’s Independent Battery, Missouri Light Artillery 3 12-pounder howitzers & 2 12-pounder Napoleons | Cpt Martin Welfley | 0 | 5 | 0 | 5 | |||
| Second Division BG Alexander Asboth (w) | First Brigade Col Frederick Schaefer | 8 | 34 | 12 | 54 | |||
| 15th Missouri Volunteer Infantry, Company B detached | Col Francis J. Joliat | 0 | 0 | 11 | 11 | |||
| Not Brigaded | 3rd Missouri Volunteer Infantry, Companies B, C, E | 0 | 0 | 0 | 0 | |||
| 4th Missouri Volunteer Cavalry Companies A, C, D, E, F, I | Maj Emeric Meszaros | 5 | 8 | 3 | 16 | |||
| Col Joseph Nemett | 3 | 11 | 3 | 17 | ||||
| Artillery | 1st Missouri Flying Artillery Battery 4 rifled 6-pounder guns & 2 12-pounder howitzers | Cpt Gustavus M. Elbert | 3 | 8 | 8 | 19 | ||
| 2nd Independent Battery, Ohio Light Artillery 4 6-pounder guns & 2 12-pounder howitzers | Lt William B. Chapman | 1 | 2 | 0 | 3 | |||
| Brigade | width=30% | Unit | width=15% | Commander | Killed | Wounded | Missing | Casualties |
|---|---|---|---|---|---|---|---|---|
| Third Division Col Jefferson C. Davis | First Brigade Col Thomas Pattison | 5 | 27 | 0 | 32 | |||
| 3 | 23 | 0 | 26 | |||||
| 22d Indiana Infantry Regiment Company B detached | Ltc John A. Hendricks (k) Maj David W. Daily, Jr. | 9 | 33 | 0 | 42 | |||
| 1st Battery, Indiana Light Artillery 4 rifled 6-pounder guns & 2 6-pounder guns | Cpt Martin Klauss | 0 | 5 | 6 | 11 | |||
| Second Brigade Col Julius White | Ltc Myron Barnes | 20 | 121 | 3 | 144 | |||
| Ltc Calvin H. Frederick | 9 | 57 | 0 | 66 | ||||
| Battery A, 2d Illinois Light Artillery 2 rifled 6-pounder guns & 2 6-pounder guns & 2 12-pounder howitzers | Cpt Peter Davidson | 0 | 17 | 0 | 17 | |||
| Not Brigaded | 1st Missouri Volunteer Cavalry Regiment Companies B, F, G, H, I, K, L, M | Col Calvin A. Ellis | 2 | 2 | 2 | 6 | ||
| Fourth Division Col Eugene A. Carr (w) | First Brigade Col Grenville M. Dodge (w) | Ltc John Galligan (w) | 18 | 139 | 3 | 160 | ||
| Col Gustavus A. Smith (w) Ltc William P. Chandler (w) | 14 | 47 | 52 | 113 | ||||
| Maj John McConnell | 9 | 36 | 13 | 58 | ||||
| 1st Independent Battery, Iowa Light Artillery 4 6-pounder guns & 2 12-pounder howitzers | Cpt Junius A. Jones (w) Lt Virgil A. David | 3 | 14 | 0 | 17 | |||
| Second Brigade Col William Vandever | Ltc Francis J. Herron (w/c) Maj William H. Coyl (w) | 38 | 176 | 4 | 218 | |||
| Phelp's Independent Infantry Regiment | Col John S. Phelps (w) | 12 | 71 | 11 | 94 | |||
| 3d Independent Battery, Iowa Light Artillery 4 6-pounder guns & 2 12-pounder howitzers | Cpt Mortimer M. Hayden | 2 | 17 | 3 | 22 | |||