2008 Western & Southern Financial Group Masters – Singles

Andy Murray defeated Novak Djokovic in the final, 7–6(7–4), 7–6(7–5) to win the men's singles tennis title at the 2008 Cincinnati Masters. It was his first Masters title. Rafael Nadal's 32 match winning-streak ended in the semifinals when he was defeated by Djokovic.

Roger Federer was the defending champion, but lost in the third round to Ivo Karlović.

Seeds
The top eight seeds receive a bye into the second round. • # Roger Federer (third round)

• # 🇪🇸 Rafael Nadal (semifinals)

• # 🇷🇸 Novak Djokovic (final)

• # 🇷🇺 Nikolay Davydenko (second round)

• # 🇪🇸 David Ferrer (second round)

• # 🇺🇸 Andy Roddick (withdrew due to a shoulder injury)

• # 🇺🇸 James Blake (third round)

• # 🇬🇧 Andy Murray (champion)

• # Stanislas Wawrinka (withdrew due to a right knee injury)

• # 🇪🇸 Fernando Verdasco (third round)

• # 🇫🇷 Richard Gasquet (second round)

• # 🇪🇸 Tommy Robredo (second round)

• # Fernando González (first round)

• # 🇷🇺 Mikhail Youzhny (first round)

• # 🇨🇿 Radek Štěpánek (first round)

• # Ivo Karlović (semifinals)