Keith, an original member of the board, takes over from Tim Hartley, who has stepped down after seven years in the role.
Keith is a director of the accountancy firm, Mazars and a football finance expert.
Keith said: "I'm delighted in the confidence shown in me by the board and I'm looking forward to the challenge. Tim will be a hard act to follow.
I particularly want to build on the good work Tim has done in building our relationship with the club at a high level, so that we can represent the views of the wider fan base in important matters."