The appointment was made with immediate effect.
Mr Fox joined Dentons in 2011 and has more than 20 years experience in the pensions and advice sector.
His career history includes Standard Life, Winterthur Life, Suffolk Life, Dominion Fiduciary and Dentons.
Martyn Rose, chairman, Dentons Pensions Management, said: “David joined us back in 2011 and has driven the sales strategy since then.
“His no nonsense approach is liked by advisers, suppliers and most importantly the internal team.
“Due to the on-going success of the business and David’s sales and marketing team we wanted to recognise his contribution to the business by asking him to join the board.”
David Fox, director of sales & marketing, Dentons Pensions Management said: “We are continuing to see growth in terms of new business and have been recruiting across the business, particularly in the sales team where we have added an additional 4 people in the past few months.
I am pleased to have been appointed to the board and look forward to continuing to lead the sales and marketing team, and helping to drive change in the business as we and the self invested market evolves.”
“We expect that 2019 will continue to be a good year for the SIPP and SSAS market as advisers look to partner with well run and well capitalised businesses that are investing in systems and people.
“Our technical expertise, depth of experience and independence make us a leading provider and administrator in the sector.”