2021 Mubadala World Tennis Championship – Men's singles

Rafael Nadal was the defending champion but lost in the semifinals to Andy Murray.

Andrey Rublev won the title, defeating Murray in the final.

Seeds
• # 🇷🇺 Andrey Rublev (champion)

• # 🇪🇸 Rafael Nadal (semifinals) (fourth place)

• # 🇨🇦 Denis Shapovalov (semifinals) (third place)

• # 🇺🇸 Taylor Fritz (quarterfinals) (fifth place)

• # 🇬🇧 Dan Evans (quarterfinals) (sixth place)

• # 🇬🇧 Andy Murray (final) (runner-up)