2021 Zadar Open

The 2021 Zadar Open was a professional tennis tournament played on clay courts. It was the first edition of the tournament which was part of the 2021 ATP Challenger Tour. It took place in Zadar, Croatia between 22 and 28 March 2021.

Seeds

 * 1 Rankings are as of 15 March 2021.

Other entrants
The following players received wildcards into the singles main draw:
 * Frane Ninčević
 * Matija Pecotić
 * Mili Poljičak

The following player received entry into the singles main draw as an alternate:
 * 🇦🇺 Harry Bourchier

The following players received entry from the qualifying draw:
 * 🇮🇹 Marco Bortolotti
 * 🇧🇦 Nerman Fatić
 * 🇧🇾 Uladzimir Ignatik
 * 🇪🇸 Nikolás Sánchez Izquierdo

The following players received entry as lucky losers:
 * 🇷🇺 Ivan Nedelko
 * 🇺🇦 Vladyslav Orlov

Singles

 * 🇷🇸 Nikola Milojević def. 🇧🇬 Dimitar Kuzmanov 2–6, 6–2, 7–6(7–5).

Doubles

 * Blaž Kavčič / Blaž Rola def. 🇸🇰 Lukáš Klein / 🇸🇰 Alex Molčan 2–6, 6–2, [10–3].