Vetlanda was still nothing more than a village for several centuries. With the 1840s population boom in Småland, and the industrial revolution winning grounds in Sweden, the industry expanded and people settled in the village. With the railways crossing Vetlanda in the late 19th century the population further blossomed, and Vetlanda got the title of a city on New Year's Day 1920, at which time its population amounted to 3,015.
The coat of arms was selected as an ear of wheat, a derivation of the arms for the old jurisdiction Östra Härad, wherein Vitala was rumoured to have been the centre, that depicted three ears of wheat. The present spelling Vetlanda did not come into use until the 1920s, before that it was known as Hvetlanda, a form that can be found in several companies and organizations.
In the 19th century, wood industry got a stronghold in Vetlanda, a seat it still has today. Manufacturing is large in Vetlanda, besides wood industries there are also a strong metal industries and other factories.