The event will take place on the streets and in squares of the spa city, and the publisher said it will be the first time a magazine has partnered with a city and its key stakeholders "on a major scale".
Victoria Archbold, director of events and sponsorship at Hearst UK, said: "This is by far our most ambitious project to date and will enable consumers to engage with the Country Living brand on an unprecedented level.
"By bringing the country to the city for four days, we hope to offer attendees an escapism from everyday life and make the festival an experience to truly remember."
The festival will run from 10 May to 13 May next year and will showcase small rural businesses, talented crafts people, artisans and designers. There will be pop-up workshops, business events, supper clubs, celebrity talks, music, entertainment and children’s activities.
David James, chief executive of Visit Bath, added: "The Country Living brand has great synergy with Bath and the event will certainly be a draw for visitors as well as residents. It will also help boost the local economy and put Bath in the national spotlight as a stylish destination."