The name Teith is obscure, but may come from the Scottish Gaelic Uisge Theamhich, which translates into English as the "quiet and pleasant water".

The place-name Callander may conserve an older name for the Teith, derived from Brittonic *caleto-dubro, meaning "hard-water".

Course

The Teith is formed from the confluence of two smaller rivers: one from Loch Venachar, the Eas Gobhain