Ms Rosser-Owen – who began her career as an editor in the publishing industry specialising in Middle East studies – said she was relishing the challenge of taking the festival forward.
“It has an offbeat brilliance and charm that audiences can lose themselves in,” she said.
“For me, returning to Wigtown feels like stepping back into a creative adventure and I’m absolutely thrilled to be back in this wonderfully unique place tucked away in south-west Scotland.
“I’m so looking forward to the organisation embracing its huge potential over the next few years.
“We have some ambitious plans ahead and I can’t wait to get stuck in and help shape what comes next.”
The full festival programme for this year will be unveiled next month after she takes over from interim chief executive Andrew McConnell.
At the same time Anne Barclay, the current operations director, will take on new role aiming to maximise support for the people and economy in and around Wigtown.