Photographs of thousands of people taken at BBC World War One at Home Live events were used to make the image of 23-year-old Pte James Ernest Beaney.
Pte Beaney’s great niece said the family were “proud and honoured”.
David Sillito reports on the mosaic, which can be seen in outside BBC Broadcasting House in London or online.
Artist Helen Marshall has been commissioned by BBC Local Radio to create The Face of World War One, containing thousands of photographs captured across the nation during the BBC World War One at Home Live Events.
Original photographs from 1914-1918 have also been included in the mosaic, supplied from the archives of Imperial War Museums and public submissions.