Barrett's Missouri Battery was an artillery battery that served in the Confederate States Army during the American Civil War. After entering Confederate service on April 1, 1862, the unit was armed with two 6-pounder smoothboore cannons and two 12-pounder howitzers and was commanded by Captain Overton W. Barrett. It was present during the Siege of Corinth, but saw no action. During the Battle of Perryville in October 1862, Barrett's battery provided artillery support for a Confederate brigade. After spending the next several months moving around Tennessee, the battery supported a Confederate attack during the Battle of Stones River in December. The 1863 Chickamauga campaign brought light action for the unit, which also fought in the Battle of Missionary Ridge. When the Confederates retreated after the Missionary Ridge fighting, Barrett's battery was part of the Confederate rear guard at the Battle of Ringgold Gap, earning the praise of Patrick R. Cleburne. Rearmed with four 12-pounder howitzers, the unit was action in the 1864 Atlanta campaign as part of the Confederate reserve artillery, although two of the cannons were lost to attrition. On April 16, 1865, the battery ceased to exist when its flag, cannons, and most of its members were captured during the Battle of Columbus, Georgia. As of January 2021, its battle flag is part of the collection of the Missouri State Museum.