Andy Roddick defeated Juan Carlos Ferrero in the final, 6–3, 6–4 to win the men's singles tennis title at the 2006 Cincinnati Masters. Roger Federer was the defending champion, but lost in the second round to Andy Murray. It would be Federer's only defeat prior to a tournament final that season.

Seeds

• # Roger Federer (second round) • # 🇪🇸 Rafael Nadal (quarterfinals) • # 🇦🇷 David Nalbandian (second round) • # Ivan Ljubičić (quarterfinals) • # 🇷🇺 Nikolay Davydenko (first round) • # 🇺🇸 James Blake (second round) • # 🇪🇸 Tommy Robredo (semifinals) • # 🇨🇾 Marcos Baghdatis (third round) • # 🇺🇸 Andy Roddick (champion) • # 🇪🇸 David Ferrer (quarterfinals) • # 🇨🇿 Tomáš Berdych (first round) • # 🇫🇮 Jarkko Nieminen (first round) • # Fernando González (semifinals) • # 🇩🇪 Tommy Haas (third round) • # 🇺🇸 Robby Ginepri (third round) • # 🇸🇰 Dominik Hrbatý (third round)

Draw

Finals

Top half

Section 1

Section 2

Bottom half

Section 3

Section 4

Qualifying

Qualifying seeds

• # 🇫🇷 Nicolas Mahut (qualified) • # 🇮🇹 Davide Sanguinetti (qualified) • # 🇮🇹 Andreas Seppi (qualified) • # 🇨🇿 Robin Vik (qualifying competition, lucky loser) • # Wesley Moodie (first round) • # 🇺🇸 Justin Gimelstob (qualified) • # 🇰🇷 Lee Hyung-taik (qualified) • # 🇫🇷 Marc Gicquel (qualified) • # 🇺🇸 Vince Spadea (qualified) • # 🇨🇿 Lukáš Dlouhý (qualifying competition, lucky loser) • # 🇺🇸 Kevin Kim (qualifying competition) • # 🇪🇨 Nicolás Lapentti (first round) • # 🇨🇿 Jan Hernych (qualifying competition) • # Kristian Pless (first round) • # 🇩🇪 Denis Gremelmayr (first round) • # Rik de Voest (qualified)

Qualifiers

• # 🇫🇷 Nicolas Mahut • # 🇮🇹 Davide Sanguinetti • # 🇮🇹 Andreas Seppi • # 🇺🇸 Vince Spadea • # Rik de Voest • # 🇺🇸 Justin Gimelstob • # 🇰🇷 Lee Hyung-taik • # 🇫🇷 Marc Gicquel

Lucky losers

• # 🇨🇿 Robin Vik • # 🇨🇿 Lukáš Dlouhý

Qualifying draw

First qualifier

Second qualifier

Third qualifier

Fourth qualifier

Fifth qualifier

Sixth qualifier

Seventh qualifier

Eighth qualifier