The 3rd Infantry, Arkansas State Troops (1861) was an Arkansas State infantry regiment that served during the American Civil War. The regiment was designated as the 2nd Infantry, Arkansas State Troops, by the State Military Board, but it was named the 3rd Arkansas by Brigadier General Nicholas Bartlett Pearce, Commander, 1st Division, Provisional Army of Arkansas. The regiment is generally referred to as the "3rd Regiment, Arkansas State Troops", or "Gratiot's Regiment" in contemporary accounts.
At the beginning of the war, the Arkansas Succession Convention created the Provisional Army of Arkansas. The Provisional Army was to consist of two divisions: the 1st Division in the western part of the state was to be commanded by Brigadier General Pearce, and the 2nd Division in the eastern half of the state, commanded by Major General James Yell. The intent of the Secession Convention was to transfer these state troop regiments into Confederate service as quickly as possible, to avoid the cost of paying for a large state army. The troops of the eastern division were transferred to the command of Brigadier General Hardee in July 1861, but the troops of the western division under Brigadier General Pearce were not transferred to Confederate service before they became engaged in the Battle of Wilson's Creek. The unit was composed of the following volunteer companies:
- Company A, Fort Smith Rifles, Commanded by Capt. James H. Sparks
- Company B, Hempstead Rifles, Commanded by Capt. John R. Gratiot
- Company C, Pike Guards, commanded by Capt. Samuel R. Bell
- Company D, Cane Hill Rifles, commanded by Capt. Pleasant W. Buchanan
- Company F, Crawford Artillery, Commanded by Capt. James T. Stewart
- Company G, Frontier Guards, commanded by Capt. Commanded by Hugh T. Brown
- Company H, Johnson Guards, commanded by Capt. Commanded by Alfred D. King
- Company K, Crawford Guards, commanded by Capt. Commanded by Joel H. Foster
Under the command of Colonel John R. Gratiot, the 3rd Regiment, Arkansas State Troops fought at the Battle of Wilson's Creek, Missouri on August 10, 1861. The unit suffered 109 casualties, including twenty-five killed, out of a force of 500 men. The regiment was marched back to Arkansas and given the opportunity to vote on the issue of being transferred into Confederate service following the battle. The regiment, along with the rest of the 1st Division voted to disband rather than be transferred to Confederate service. Many veterans of the regiments joined other Confederate units later in the war.