Isthmian

Isthmian is the adjective pertaining to an isthmus.

It may also refer to:


 * Isthmian Games, one of the Panhellenic Games of Ancient Greece
 * Isthmian League, a regional football league covering London and South East England
 * Isthmian script, one of the Mesoamerican writing-systems
 * Isthmian Steamship Company, a shipping company
 * Isthmian Canal Commission, an American administration commission set up to oversee the construction of the Panama Canal