The Royal British Legion's Poppy Appeal starts on Wednesday with a concert fronted by singers Alesha Dixon and Pixie Lott and soldier Sapper Clive Smith as the face of the appeal.
Sapper lost both his legs in Afghanistan in 2010 and said it was great to give something back.
"The ongoing support I've received from Battle Back Centre staff and others over the course of my recovery has been invaluable.
Sapper Clive Smith said he was incredibly grateful for the support. He met the Duchess of Cambridge during a reception to celebrate the Scott-Amundsen Centenary Race to the South Pole at Goldsmiths Hall, London
"It's humbling to know that the centre has been created because of the public's generous support of the Legion, and the Poppy Appeal in particular.
"Without it, the Legion would not be able to help guys like me, as well as people who have left Service and their families.
"I'm glad to be giving my support to the charity by being at the launch and also being in the Poppy Appeal poster campaign."
He will be present at the free event in Trafalgar Square in London marking the start of the Legion's £42 million fundraising drive.
The concert will also feature The Military Wives Choir and James Fox, star of the West End musical Let It Be, who will sing the official Poppy Appeal 2012 single Landlocked.
Singers Alesha Dixon and Pixie Lott are also performing at the event
The appeal's £42 million target is up on the record £40 million raised last year.
People wishing to donate can do so at any time through the internet or by text.
Poppies will go on sale from Saturday until November 11, at locations across the country including train and Tube stations and shopping centres.
Poppies are worn in remembrance of those who gave up their lives our freedom
The Royal British Legion spends £1.7 million a week on care and support for military families, including grants, employment advice and funding, emotional support, tribunal and inquest advice, care homes and family breaks.
The act of observing a two-minute silence each year on 11 November began in remembrance of the Armistice agreement between the Allies and Germany which was signed at 11am on November 11, 1918 to mark end of the First World War.
Its work includes help for service personnel returning from Afghanistan as well as those from past conflicts.
The Legion is giving £50 million over 10 years to support the recovery of wounded, injured and sick service men and women.