Brooke, who worked at Channel 4 for seven years up to 2005, will head up a combined marketing, communications and corporate relations group, reporting directly to chief executive David Abraham.
His job is among a number of positions created by Abraham as part of a major revamp of the Channel 4 management structure.
Brooke first joined Channel 4 in 1998 as head of marketing and development for Film4, but went on to become managing director of the broadcaster's digital channels, overseeing the launch of E4 and More4.
He left Channel 4 in 2005 to become managing director of Discovery Networks UK, but rejoins from independent production firm Rare Day, where he was also managing director.
"Having been the driving force behind the birth of Channel 4's portfolio of digital channels Dan is returning here at the dawn of digital convergence, an era where communication with all of our audiences will be more vital than ever to the success of Channel 4's mission," said Abraham.
"Over his varied career he has shown an ability to innovate, in both the public service and commercial worlds."
Brooke added: "Progressive cultures, like ours, need independent, iconoclastic forces to help keep them that way. I love Channel 4 and everything it stands for and I look forward to leading its award-winning marketing and communications team through this next exciting chapter of its story."