Gurassa's appointment comes just months after leaked documents suggested the Government might consider selling Channel 4 for £1bn.
He is currently deputy chairman of easyJet, chairman of the Genesis Housing Association, a trustee of English Heritage and a senior independent director for Merlin Entertainments.
His executive career included roles as chief executive of Thomson Travel Group and executive chairman of TUI Northern Europe. He is also a former chairman of Virgin Mobile and Lovefilm, and a former deputy chairman of the National Trust.
Mr Gurassa said: "I am excited to be joining Channel 4, which has a unique place in UK broadcasting. I look forward to exploring Channel 4's important contribution in a rapidly changing sector."
Dame Patricia Hodgson, Ofcom chairman, added: "I am delighted that we have appointed a chairman of Charles's calibre to Channel 4. He brings with him a wealth of experience built up across a broad range of sectors.
"I would also like to thank Lord Burns, Channel 4's chairman for the past six years. He has made a tremendous contribution to the success of Channel 4."
Ofcom said Mr Gurassa's appointment as chairman for three years has been approved by the Secretary of State for Culture, Media and Sport John Whittingdale.
The broadcasting watchdog is required under the Broadcasting Act 1990 to appoint non-executive members to the Channel 4 board, subject to the approval of the Secretary of State.
It had been reported last year that Waitrose managing director Mark Price was being lined up to become the interim chairman of Channel 4 when Lord Burns ended his term.
Maria Eagle, Labour's shadow culture secretary, said: "We welcome Charles Gurassa to his new role as chairman at Channel 4. With the threat of privatisation hanging over it, this comes at a difficult time for the much-loved broadcaster.
"Labour will continue to fight any attempts by Tory ministers to sell off Channel 4."