The four-year partnership between the two travel bodies will capitalise initially on the Diamond Jubilee and the London 2012 Games.
STA Travel joins brands such as British Airways and easyJet, helping to fund VisitBritain's £100m spend on its 'You’re invited' global campaign.
STA Travel’s part in the campaign will be showcased in designated international markets – Australasia, China, Japan, Russia and the US – to attract young travellers.
Sandie Dawe, chief executive of VisitBritain, said: "This agreement is an opportunity for VisitBritain to utilise the expertise that STA Travel has overseas and will help bring an added focus for our ‘Great Britain You’re Invited’ campaign in the all-important youth travel market.
"Britain is already a leading international destination for overseas visitors and our marketing programme aims to ensure we continue to compete and grow the value of tourism to this country, against fierce global competition."