The 13th Arkansas Infantry (1861–1865) was a Confederate Army infantry regiment during the American Civil War. Organized mainly from companies, including several prewar volunteer militia companies, raised in northeastern Arkansas, the regiment was among the first transferred to Confederate Service, and spent virtually the entire war serving in Confederate forces east of the Mississippi River. After the unit sustained heavy casualties during the Battle of Murfreesboro, the unit spent most of the rest of the war field consolidated with the 13th Arkansas Infantry Regiment, to form the 5th/13th Arkansas Infantry Regiment.

The 15th Arkansas Infantry Regiment or Josey's Arkansas Infantry Regiment was an infantry formation in the Confederate States Army during the American Civil War. The regiment was organized in May 1861 under the command of Colonel Patrick Cleburne. It served throughout the war in the western theater, seeing action in the Kentucky, Tennessee, and Georgia campaigns. Following its depletion in numbers the regiment was consolidated several times with other Arkansas regiments, finally merging in 1865 into the 1st Arkansas Consolidated Infantry Regiment. There were two other regiments which also received the designation of "15th Arkansas". The 21st (McRae's) Arkansas Infantry was redesignated 15th Arkansas in February 1863, but to avoid confusion, was normally referred to as the "Northwest regiment". This second "15th Arkansas" was surrendered at Vicksburg in July 1863. A third regiment, under command of Colonels Gee and later Johnson, also received the designation 15th Arkansas Infantry. This last regiment surrendered at Port Hudson, Louisiana, in July 1863.