Rich, who joins on February 17, 2021, was most recently chief executive of TI Media and led the sale of NME.com to Bandlab Technologies, and oversaw the overall sale of the business to Future PLC. He replaces Robin Miller, who made the decision to step down from Digitalbox in October last year.
In a statement, James Carter, Digitalbox's chief executive, said: "I very much look forward to working with Marcus as we continue to build our business through further acquisitions and diversification.
"The media market is responding well to our approach and I have absolute confidence that with Marcus's assistance and his experience working for leading media organisations Bauer Media, Daily Mail and General Trust and TI Media, we can steer the best possible course during these times of intense innovation and growth."
Rich said: "I've been hugely impressed by the progress Digitalbox has made in a few short years.”
Digitalbox owns online titles such as Entertainment Daily, The Daily Mash and The Tab,