In the newly created role Fosbury will be responsible for "developing and driving the marketing strategy as Digicom ramps up into its next stage of growth", with a focus on sales.
Fosbury joins Digicom from Northern & Shell, where she has been working since June 2008 heading up the research department working across titles including the Daily and Sunday Express, The Daily Star, OK!, Star and New! magazines.
Prior to Northern & Shell she held the role of marketing director at Emap Advertising.
Fosbury said: "I believe that what Digicom is planning for the future is truly exciting and ground-breaking, and I am looking forward to the opportunity to work with the team to shape the next stage of growth."
The outdoor specialist has also strengthened its sales team with the appointment of Robbie MacAskill as activation manager, where "he will be responsible for identifying opportunities available through alternative advertiser budget streams", and working across Digicom's growing portfolio of retail convenience networks.
He joins after spending four years at Haymarket Business Media where he was sales manager on trade title Windpower Monthly.
Chris Forrester, Digicom managing director, said: "We are delighted to have attracted someone of Sam's calibre and experience to the marketing team.
"Her breadth of experience across media and across the marketing mix make her an invaluable addition for Digicom as we move into our second year as a company and continue to gain ground in digital out of home media.
"Robbie's appointment is an exciting addition to us in the sales team, as it will enable us to unlock additional revenue streams from below the line budgets while maximising the opportunities the networks we represent can deliver to advertisers."
Fosbury replaces Liz Ross Martyn who has poached for the position of head of marketing communications at out-of-home company JC Decaux Airport.