The 2023 Zadar Open was a professional tennis tournament played on clay courts. It was the third edition of the tournament which was part of the 2023 ATP Challenger Tour. It took place in Zadar, Croatia between 20 and 26 March 2023.

Country	Player	Rank1	Seed
TPE	Tseng Chun-hsin	125	1
SVK	Jozef Kovalík	145	2
GBR	Ryan Peniston	152	3
AUT	Sebastian Ofner	160	4
ITA	Flavio Cobolli	165	5
FRA	Laurent Lokoli	168	6
CZE	Vít Kopřiva	169	7
FRA	Manuel Guinard	177	8

• ¹ Rankings are as of 6 March 2023.^[1]

The following players received wildcards into the singles main draw:

• Duje Ajduković
• Mili Poljičak
• Dino Prižmić

The following players received entry from the qualifying draw:

• Mirza Bašić
• Giovanni Fonio
• Jeremy Jahn
• Julian Ocleppo
• David Pichler
• Giulio Zeppieri

The following players received entry as lucky losers:

• Salvatore Caruso
• Nikola Milojević

• Alessandro Giannessi def. Sebastian Ofner 6–4, 5–7, 7–6^(8–6).

• Manuel Guinard / Nino Serdarušić def. Ivan Sabanov / Matej Sabanov 6–4, 6–0.