Allmersbach im Tal was first mentioned in 1291, relating to the gifting of goods from the Countess Richinza von Löwenstein to the Teutonic Order of Winnenden. Owing to this gifting, Manorialism came into the hands of the Dominican Monastery Weiler bei Esslingen. In the 16th century the Reformation lead to the town falling under the jurisdiction of Württemberg. Until 1712 Allmersbach im Tal belonged to the monastery court mastery and until 1807 to the monasterial administration of the monastery Weiler bei Esslingen.
The municipality of Allmersbach im Tal was formed on 1 January 1972, as part of the 1968-75 Baden-Württemberg municipal reforms [de], by the merging of the towns of Allmersbach and Heutensbach.[2]
Allmersbach's coat of arms displays a crossbow, in red and with its trigger guard facing right, upon a field of silver. The crossbow is a motif that has been associated with Allmersbach since 1686, though it is not known why, and the tincture is taken from the arms of the County of Löwenstein [de], which had property in the town. The coat of arms was approved for official use and a corresponding municipal flag issued by the Federal Ministry of the Interior on 16 September 1965.[2]