Evans will work closely with chief executive Brian Raven and, as the title suggests, will be responsible for all business development activity across the group.
This will range from considering potential acquisitions to establishing strategic partnerships, Tavistock said.
The new role is not a main board position.
Evans has almost three decades of business experience and industry, having worked in financial services both in the UK and overseas since the late eighties.
“[Mark] is a very experienced strategic thinker who understands both the market in which we operate and our aspirations as a business,” said chief executive Raven.
“A true ideas person - he is the ideal man to lead our business development activity.”
Shares were down 2% to 2.75p in afternoon trading.