You can obtain your marriage license from any Tennessee County 

There are 3 locations here in SEVIER County where you can obtain your
TN marriage license once you arrive into town.
There is a county clerk in Gatlinburg, Pigeon Forge (Open Saturdays Only) and in our county seat, Sevierville.

The Location, Phone Number, Hours of Operations for each location
as well as the requirements for obtaining your TN marriage license can be found
on the http://www.seviercountytn.gov/.

Please check this information before arriving to town as hours and days of the week they are open change periodically.

You can apply online within 30 days of your wedding and pick it up when you get into town.  You both need to be present with the proper ID.