2018 Internazionali di Tennis Castel del Monte

Country	Player	Rank1	Seed
FRA	Ugo Humbert	98	1
ITA	Lorenzo Sonego	108	2
ITA	Paolo Lorenzi	115	3
ESP	Adrián Menéndez Maceiras	126	4
UKR	Sergiy Stakhovsky	138	5
FRA	Quentin Halys	141	6
FRA	Corentin Moutet	156	7
ITA	Filippo Baldi	178	8

• ¹ Rankings are as of 12 November 2018.^[1]

The following players received wildcards into the singles main draw:

• Liam Caruana
• Julian Ocleppo
• Andrea Pellegrino
• Jannik Sinner

The following player received entry into the singles main draw as an alternate:

• Alessandro Bega

The following players received entry from the qualifying draw:

• Lorenzo Frigerio
• Illya Marchenko
• Aldin Šetkić
• Tobias Simon

The following players received entry as lucky losers:

• Alexander Erler
• Marc-Andrea Hüsler

• Ugo Humbert def. Filippo Baldi 6–4, 7–6^(7–3).

• Karol Drzewiecki / Szymon Walków def. Marc-Andrea Hüsler / David Pel 7–6^(12–10), 2–6, [11–9].