Allison Nelson (March 11, 1822 – October 7, 1862) was the ninth mayor of Atlanta, serving from January until July 1855, when he resigned from office.

In a close election for mayor, Nelson, running as a Democrat, defeated the Know Nothing candidate, Ira O. McDaniel, but resigned in July when the city council reduced a fine he had levied on two young men for destroying city property, thus leaving John Glen as the acting mayor.

Nelson left for Kansas during the border disputes, then moved to Meridian, Texas, where he was involved with Indian affairs, serving under Lawrence S. Ross, and in 1860 was elected to the legislature.

He organized and served as colonel of the 10th Texas Infantry Regiment in the Confederate States Army.

Camp Nelson Confederate Cemetery (established 1897) in Lonoke County, Arkansas, is named after him.