2023 Mutua Madrid Open – Men's singles

Defending champion Carlos Alcaraz defeated Jan-Lennard Struff in the final, 6–4, 3–6, 6–3 to win the men's singles tennis title at the 2023 Madrid Open. It was his fourth Masters 1000 title. Struff was the first lucky loser to reach a Masters final.

This was the first edition in the tournament's 21-year history to not feature Roger Federer, Rafael Nadal, or Novak Djokovic (collectively known as the Big Three) in the main draw. They won 11 of the preceding 16 editions of the Madrid Open, reaching 13 finals in total.

Zhang Zhizhen was the first Chinese man to reach the singles quarterfinals of a Masters event. Aslan Karatsev was only the second qualifier to reach the Madrid Open semifinals, after Fabrice Santoro in 2002. The semifinal encounter between Karatsev and Struff was a rematch of their meeting in the qualifying rounds of the tournament, which Karatsev had won; Struff won their semifinal rematch.