The agency, headed by Sophy Norris, director of Flagship Consulting South West, won the brief after a five-way shoot-out.
The team will handle press and media activity for a campaign to promote the area as a year-round destination for visitors. The agency will seek to take advantage of both local and national events across a busy British calendar.
Norris said: 'This is a very exciting project. Central to our campaign is positioning Wiltshire as a place worth visiting, as there is so much to see and do.
'We want visitors to take the time to explore its beautiful scenery and rich history.'