Category:2000s music groups
- All Systems Go!
- All That Remains (band)
- All Time Low
- The All-American Rejects
- The Alley Cats
- The Alligators
- The Almost
- AlogiA (band)
- Alon Yavnai-Paquito D'Rivera Duet
- Alpinestars (band)
- Altar Boys
- Alter Bridge
- Alter Der Ruine
- Alter Ego (band)
- Aluna
- Aly & Fila
- Amateur God
- Amazing Rhythm Aces
- Amber Pacific
- The Amenta
- American Juniors
- Amethystium
- Amici Forever
- Amity Lane
- Amon Amarth
- Amoral (band)
- Amplifier (band)
- Amungus
- Amusement Parks on Fire
- Anabantha
- Anata
- Anberlin
- Ancestors (band)
- Anchor & Braille
- Ancient Rites
- Andakat
- Andeline
- Anemic (band)
- Angelcorpse
- An Angle
- Anima pop
- Animal Collective
- Ankla
- Annihilator (band)
- The Anniversary
- Another Animal
- Another Black Day
- Ant & Dec
- Antediluvian Rocking Horse
- Anterior (band)
- Anterrabae
- Antistatic (band)
- Antony and the Johnsons
- Anvil (band)
- Anvil of Doom
- Anyband
- Anything But Monday
- Apache Beat
- Apartment (band)
- Apocalypse (band)
- Apocalypse Hoboken
- Apostle of Hustle
- The Apples in Stereo
- The Appreciation Post
- April Wine
- Aqua (band)
- Aqua Timez