The 40-year-old starts tomorrow after last week completing a spell of ‘gardening leave’ following his decision to quit the Bantams in June.
Mason, a former BBC journalist, joined City when Mark Lawn and Julian Rhodes were in charge of the League One club.
“I have long been an admirer of Rochdale football club from my visits here as an opposing director and visiting fan,” said Mason.
“They have a great reputation within the industry for being well run on and off the field and have a team of really talented and committed people working here already.
“My immediate role will be to offer my experience, advice and leadership in the areas where it is needed.”
Mason last week launched sports agency, ‘FIVE NINE’, along with long-term friend Geoff Gray, who will run the business to leave Mason free to focus on his new full-time role at Rochdale.
He added: “The board care passionately about the club. Keith (Hill) is a manager that I greatly admire. The youth set up speaks for itself, as highlighted by the emergence of players like Luke Matheson.
“I am also fully aware of the loyal and proud fan base. I am sure I will get to know everyone in due course and adding value where I can.
“I have a long association with Rochdale with close family in Littleborough. My cousins support the club and my uncle was a very active sportsman within the area as I was growing up.
“Last year I donated some season tickets myself to acknowledge the lower prices, something I am a big believer in.
“Since leaving Bradford in the summer I have spent a lot of time watching and researching how other sports operate.
“I have a number of senior contacts in cricket and rugby as well as football. To observe and share some good practices with them over the last few weeks has been invaluable.
“I am really looking forward to getting started.”