Istrian Social Democratic Forum

Istrian Socialdemocratic Forum (Istarski socijaldemokratski forum, ISDF, Foro social democratico Istriano, FSDI) was a regional left-wing political party in Istria County of Croatia.

It was founded by dissident faction of Istrian Democratic Assembly and firstly it was named Istrian Democratic Forum, led by Luciano Delbianco, former prefect of Istria County.

In the past, it has usually been allied with Social Democratic Party of Croatia, but is currently allied with a number of small leftist parties, such as the Left of Croatia.