In an email to BBC staff, Hall outlined key challenges and said he hopes to “win back trust” for the corporation.
"In the coming weeks, I will set out how we can all shape the next chapter for the BBC as we move towards our centenary in 2022," said Hall.
His appointment as director-general is not the first time Hall has worked for the BBC. He was the head of news and current affairs from 1996 to 2001, and oversaw the launch of Radio 5 live, BBC News 24, the BBC News website and BBC Parliament.
Hall comes in at a crucial time for the BBC. Former Director George Entwistle held the position for only 54 days, resigning after the Jimmy Savile and Lord McAlpine child abuse scandals. One of Hall's first tasks will be to appoint a new director of news and a director of television.
The BBC reports that “the news role is particularly important following the handling of the two Newsnight crises - one over the failure to broadcast the original investigation into allegations against Jimmy Savile and the subsequent programme that led Lord McAlpine to be wrongly implicated in claims of child abuse.”