Scott was at Channel 4 for its launch in 1982 as controller of finance. He went on to hold the posts of director of finance, managing director and deputy chief executive.
He has sat on the board of Digital UK as Channel 4's representative, even after leaving the broadcaster in 2005.
Barry Cox, chairman of Digital UK, said: "David has been closely involved in switchover, both during his time at Channel 4 and more recently on the board of Digital UK.
"His understanding of the unique challenges of this project, combined with his many years of wider broadcasting experience, will ensure the process continues to be expertly managed and that viewers are kept well informed."
The digital switchover process began last month with a small-scale roll-out in the Cumbrian town of Whitehaven, which has around 25,000 households.
The next area to switch over to digital will be the Scottish Borders in November 2008, followed by the West Country, Wales and Granada starting in 2009.
The analogue signal will be completely switched off in 2012.