2021 Zadar Open

Country	Player	Rank1	Seed
ITA	Gianluca Mager	101	1
IND	Sumit Nagal	139	2
SRB	Nikola Milojević	146	3
SLO	Blaž Rola	165	4
ITA	Alessandro Giannessi	167	5
SVK	Filip Horanský	173	6
FRA	Enzo Couacaud	185	7
ITA	Gian Marco Moroni	233	8

• ¹ Rankings are as of 15 March 2021.^[1]

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

• Nikola Milojević def. Dimitar Kuzmanov 2–6, 6–2, 7–6^(7–5).

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