Tony Hall has hired Purnell to become director of strategy and digital. His remit will include running the strategy, digital, communications, policy, public affairs, marketing and audiences divisions.
PRWeek understands that he will be brought in above Paul Mylrea, who was director of communications but had his role changed in September to director of public affairs.
In an email to staff, Hall said that the appointments were part of helping ‘deliver a new strategy and creative vision’ for the broadcaster.
He said that the appointment of Purnell into the new role was a key part on putting ‘a big emphasis on what we want the future role of the BBC to be.’
He added: ‘Thinking about future media is critical to the BBC and so joining that up with our strategic thinking should help us define the most powerful possible case for public service broadcasting.’
Purnell, who will sit on the broadcaster's executive board, is currently a senior producer at Rare Day and adviser to the Boston Consulting Group.
He served in the Labour government as Secretary of State for Culture, Media and Sport from 2007, moving to become Work and Pensions Secretary in early 2008.
Purnell stepped down from the Labour front benches in June 2009 after criticising the leadership of then-Prime Minister Gordon Brown. He left parliament in 2010 after deciding against contesting his Stalybridge and Hyde seat at the general election.
In 2010 Purnell held talks with a number of PR agencies, before assuming his roles at Rare Day and Boston Consulting.
Before becoming an MP in 2001, he worked at the BBC as head of corporate planning from 1995 to 1997.
Hall, who will be joining in April, has also made a number of other senior appointments ahead of his arrival.
These include Helen Boaden being named director of radio (formerly audio and music) and acting director general Tim Davie becoming director of global and CEO of BBC worldwide.