This is a timeline documenting the events of heavy metal in the year 2003.

Newly formed bands

• Born of Osiris
• Communic
• DevilDriver
• Epica
• Equilibrium
• Korpiklaani
• Sturmgeist
• Sybreed
• Wicked Wisdom

Reformed bands

• 24-7 Spyz
• Europe
• Fear Factory
• Judas Priest
• Primus
• Stryper

Albums

• Alice Cooper - The Eyes Of Alice Cooper
• Akercocke - Choronozon
• Arch Enemy - Anthems of Rebellion
• Avenged Sevenfold - Waking the Fallen
• Black Label Society - The Blessed Hellride
• Bon Jovi - This Left Feels Right
• Cannibal Corpse - 15 Year Killing Spree
• Children of Bodom - Hate Crew Deathroll
• Chimaira - The Impossibility of Reason
• Cog - Open Up
• Cradle of Filth - Damnation and a Day
• The Darkness - Permission to Land
• Deep Purple - Bananas
• Devildriver - DevilDriver
• Dimmu Borgir - Death Cult Armageddon
• Divinity Destroyed - Divinity Destroyed
• Divinity Destroyed - Eden in Ashes
• DragonForce - Valley of the Damned
• Dream Theater - Train of Thought
• Europe - Rock the Night: The Very Best of Europe (Compilation Album)
• Finntroll - Visor om Slutet'
• Gojira - The Link
• Gojira - Maciste All Inferno (EP)
• Helloween - Rabbit Don't Come Easy
• Iron Maiden - Dance of Death
• Judas Priest - Livin' after Midnight
• Kiss - Kiss Symphony: Alive IV
• Kreator - Live Kreation
• Lamb of God - As the Palaces Burn
• Living Colour - Collideøscope
• Macabre - Murder Metal
• Marilyn Manson - The Golden Age of Grotesque
• Metallica - St. Anger
• Moonspell - The Antidote
• Motörhead - Live at Brixton Academy
• No Big Silence - Unreleased
• Opeth - Damnation
• Pitchshifter - Bootlegged, Distorted, Remixed and Uploaded
• Skid Row - Thickskin
• Solefald - In Harmonia Universali
• Sonata Arctica - Winterheart's Guild
• Static-X - Shadow Zone
• Strapping Young Lad - Strapping Young Lad
• Stratovarius - Elements, Pt. 1
• Stratovarius - Elements, Pt. 2
• Stryper - Seven
• Theocracy - Theocracy
• Tourniquet - Where Moth and Rust Destroy
• Trivium - Ember to Inferno
• Týr - Eric the Red
• uneXpect - WE, Invaders
• Virgin Black - Elegant... and Dying

Disbandments

• Coal Chamber
• Five pointe o
• Limbonic Art
• Immortal
• Pitchshifter
• Pantera

Events

• Metallica hires new bassist Robert Trujillo (from Suicidal Tendencies and Ozzy Osbourne).
• MTV2 resurrected the old heavy metal/hard rock television program Headbangers' Ball.
• Iced Earth vocalist Matt Barlow leaves Iced Earth after the events of September 11th.
• Christian metal band Stryper reforms with all original members.
• Visions of Atlantis lead vocalist Christian Stani quits, and is later replaced by Mario Plank. Keyboardist Chris Kamper quits and is replaced by Miro Holly
• Rob Halford reunites with Judas Priest replacing Tim "Ripper" Owens
• Aerosmith and KISS embark on a tour together