Manchester-based Landscape Projects' entry has been chosen for the redevelopment of the space, as part of a competition to redesign six public squares in Lancashire.
The winning entry proposes creating a flexible open space in front of the town hall and lighting key buildings. The design team's ideas include tree planting, seating and a dramatic cast-iron curve telling the story of the town.
Landscape Projects principal Neil Swanson said: "For us, Accrington is a fine town, one of the jewels of Pennine Lancashire, which needs a proper public place at its heart - a place for meeting, for markets, celebrations and events. We can't wait to get going."
The Landscape Institute is running the competition with regeneration agency Elevate.
Winners for the five other Pennine Lancashire towns - Blackburn, Bacup, Clitheroe, Burnley and Nelson - are being selected after the judges received 78 expressions of interest from across the world.