National Lottery Good Causes, its charitable arm, will be working with PrettyGreen, which won the work following a pitch.
The four-month brief tasks the agency with highlighting Games volunteers, known as Gamesmakers, who continued to volunteer for National Lottery-funded good causes after the Games.
PrettyGreen’s joint MD Emma Grace will lead the work, with the support of an eight-strong team across production, PR and digital.
She said: ‘The strategy is focused on content creation, shining a spotlight on the Gamesmakers a year after London 2012 and celebrating the impact they continue to make to National Lottery-funded causes.
‘That’s everything from volunteering at the Science Museum, to Stonehenge, to the Welsh Ambulance Service to The Lowry arts centre in Manchester.'
Planned activity will have a strong online presence, Grace said, with the one-year anniversary not the main focus of the brief but ‘likely to provide a natural news hook’.
Significant National Lottery funding went into London 2012, with £2.2bn pumped into the infrastructure of the Olympic Park. However, in April, the Public Accounts Committee said the volunteering spirit seen last summer risked ‘fizzling out’.
Meanwhile, the National Lottery Promotions Unit, which oversaw the appointment process for PrettyGreen, is also looking to hire an agency for a brief worth up to £250,000 to promote the National Lottery more widely.