The agency will be in charge of consumer media relations for Edinburgh's Christmas and Hogmanay events.
Eight agencies were involved in the tender process. The client, which is part of the City of Edinburgh Council, met with four agencies before making its decision.
Stripe has been asked to promote Edinburgh as a destination in local, national and international press, drive attendance to the events and work with sponsors and partners.
Associate director Morna McLelland will head up the year-long account, reporting into marketing and communications manager John-Paul Murphy.
'There are signs that people are travelling abroad less, so we will be trying to capitalise on that', said Murphy.
The festivals had negative press in 2006/7 after high winds caused the Hogmanay street party to be cancelled. Stripe will emphasise the range of events the festivals provide that are not reliant on the weather.
CM Porter Novelli held the account for the past two years. It is believed to have repitched for the business, alongside Scottish powerhouse 3X1.
The festivals have a huge economic impact on the Scottish capital, bringing in £136m since 2004. Over 500,000 visitors are expected this year.