Zagreb Open
Image:ChristopheRochusStuttgart06.jpg|thumb|200px|Belgian Christophe Rochus defeated Carlos Berlocq in the 2008 final
Image:Tipsarevic.jpg|thumb|200px|Janko Tipsarević from Serbia was the winner of the 2007 singles event
Image:IvanLjubicic GerryWeberOpen2008.jpg|thumb|200px|1997 singles runner-up and 1999 doubles champion Ivan Ljubičić was the first Croatian to win the singles title in 2005
The Zagreb Open is a professional tennis tournament played on outdoor red clay courts. It is part of the ATP Challenger Tour and of the ITF Women's World Tennis Tour. It was held annually at the Sportski park Mladost in Zagreb, Croatia, from 1996 to 2011. The men's tournament returned in 2021 and was played for two years at the Tenis centar Maksimir. After another break in 2023 the tournament moved in 2024 to the Sportsko rekreacijski centar Šalata. The women's tournament returned in 2024, played also at the SRC Šalata.
Tom Vanhoudt is the doubles record holder with two titles, along with Ágnes Szávay on the women's counterpart with one single and one doubles title.