2018 Italian Open – Men's singles

Rafael Nadal defeated the defending champion Alexander Zverev in the final, 6–1, 1–6, 6–3 to win the men's singles tennis title at the 2018 Italian Open. It was his record-extending eighth Italian Open title and his record-extending 32nd Masters title overall. With the win, Nadal also regained the ATP No. 1 singles ranking.

After failing to defend his runner-up points from the previous year, Novak Djokovic fell outside the Top 20 in rankings for the first time since October 2, 2006.

This was the last professional tournament for former world No. 13 Alexandr Dolgopolov. He lost in the first round to Djokovic.

Seeds
The top eight seeds receive a bye into the second round. • 🇪🇸 Rafael Nadal (champion)

• 🇩🇪 Alexander Zverev (final)

• 🇧🇬 Grigor Dimitrov (second round)

• Marin Čilić (semifinals)

• 🇦🇷 Juan Martín del Potro (third round, retired)

• 🇦🇹 Dominic Thiem (second round)

• Kevin Anderson (second round, retired)

• 🇺🇸 John Isner (second round)

• 🇧🇪 David Goffin (quarterfinals)

• 🇪🇸 Pablo Carreño Busta (quarterfinals)

• 🇷🇸 Novak Djokovic (semifinals)

• 🇺🇸 Sam Querrey (first round)

• 🇺🇸 Jack Sock (second round)

• 🇦🇷 Diego Schwartzman (second round)

• 🇨🇿 Tomáš Berdych (first round)

• 🇫🇷 Lucas Pouille (second round)

Seeds
• # Stefanos Tsitsipas (qualified)

• # João Sousa (qualifying competition)

• # 🇩🇪 Mischa Zverev (qualifying competition)

• # 🇺🇸 Frances Tiafoe (qualified)

• # 🇫🇷 Julien Benneteau (qualifying competition)

• # 🇭🇺 Márton Fucsovics (first round)

• # 🇹🇳 Malek Jaziri (qualified)

• # Nicolás Jarry (qualified)

• # 🇺🇸 Taylor Fritz (first round)

• # 🇪🇸 Guillermo García López (qualifying competition)

• # 🇩🇪 Florian Mayer (first round)

• # Nikoloz Basilashvili (qualified)

• # 🇦🇷 Federico Delbonis (qualified)

• # 🇷🇸 Viktor Troicki (qualifying competition, withdrew)

Qualifiers
• # Stefanos Tsitsipas

• # Nicolás Jarry

• # 🇦🇷 Federico Delbonis

• # 🇺🇸 Frances Tiafoe

• # Nikoloz Basilashvili

• # 🇮🇹 Filippo Baldi

• # 🇹🇳 Malek Jaziri