Istrian Spring Trophy (Croatian: Istarsko proljeće) is a stage road bicycle race held annually in the Croatian part of the Istria peninsula.

The race was first organized in 1961 as a small competition reserved to local cyclists.

In 2000, it was opened to professional riders; since 2005, it is rated as a 2.2 event on the UCI Europe Tour.

Before 2006, the race was called "Jadranska magistrala".

The 2012 edition of the race featured a prologue and three stages totaling 487 kilometres (303 mi), and was contested by more than 200 cyclists from 35 teams.