Moore died of a massive heart attack, associated with consumption of large amounts of alcohol, at the age of 58 during the early hours of 6 February 2011. At the time, he was on holiday at the Kempinski Hotel in Estepona, Spain, with his girlfriend, who raised the alarm at 4:00 am. His death was confirmed by Thin Lizzy's manager Adam Parsons. Tests revealed that Moore died after consuming huge amounts of alcohol. He had 380 mg of alcohol per decilitre of blood in his system – 30 mg more than the amount usually associated with such deaths. Although he wasn't driving, that amount would have put him nearly five times over the legal limit for driving in the UK.
Moore was laid to rest in St Margaret's Churchyard, Rottingdean, East Sussex, England, which is close to Brighton, in a private ceremony with only the family in attendance.