It is not known if Damon - who now fronts Gorillaz and The Good The Bad and the Queen - and Graham, who has just released his eighth solo album, will perform any Blur tracks, or appear on stage together at the event.
War Child Music Director, Ben Knowles, said: "War Child's annual BRIT Awards show has become a unique and important date in the music calendar.
"We believe music can make a difference, it can change lives. This year's amazing line-up will prove that - it will make for a stunning, unforgettable night and one that will raise money to help thousands of children affected by war."
Blur - which also includes Dave Rowntree and Alex James - will receive the Outstanding Contribution To Music Award at the BRITs, held on February 21 at London's The O2 venue, where they will also perform.
The War Child fundraising show will take place at London O2 Shepherd's Bush Empire venue on February 19.