2021 Queen's Club Championships – Singles

Matteo Berrettini defeated Cameron Norrie in the final, 6–4, 6–7(5–7), 6–3, to win the singles tennis title at the 2021 Queen's Club Championships. Berrettini's win earned him his fourth career ATP Tour singles title, his first ATP 500 victory, and also made him the first player to win the tournament on their main draw debut since Boris Becker in 1985. Norrie was contesting for his first title in his fourth career final.

Feliciano López was the defending champion from when the event was last held in 2019, but he lost in the second round to Denis Shapovalov.

Seeds
• #🇮🇹 Matteo Berrettini (champion)

• #🇨🇦 Denis Shapovalov (semifinals)

• #🇮🇹 Jannik Sinner (first round)

• #🇦🇺 Alex de Minaur (semifinals)

• #🇷🇺 Aslan Karatsev (second round)

• #🇬🇧 Dan Evans (quarterfinals)

• #🇮🇹 Lorenzo Sonego (first round)

• #🇮🇹 Fabio Fognini (second round)

Seeds
• # 🇫🇷 Lucas Pouille (first round)

• # 🇪🇸 Bernabé Zapata Miralles (qualifying competition)

• # Botic van de Zandschulp (first round)

• # Marc-Andrea Hüsler (first round)

• # Jason Jung (first round)

• # 🇺🇦 Illya Marchenko (qualified)

• # Alejandro Tabilo (qualifying competition, lucky loser)

• # 🇦🇹 Sebastian Ofner (qualified)

Qualifiers
• # 🇷🇸 Viktor Troicki

• # 🇦🇹 Sebastian Ofner

• # 🇺🇦 Illya Marchenko

• # 🇦🇺 Aleksandar Vukic

Lucky loser
• # Alejandro Tabilo