The law firm is to relocate from offices in City Wharf to Deva City Office Park in Salford.
Stephensons took 4,800 sq ft over two floors in the Brewery Yard building and will move around 30 staff from its current premises by late November.
The Manchester office move is part of a 12-month programme of office upgrades across Stephensons' offices. The law firm said it is making the investment in its premises following a period of extensive growth and research into how customers are accessing legal services.
The firm was assisted in sourcing and negotiating the lease at Deva City Office Park by Andrew Frazer, a director at Scott Frazer Property Consultants in Manchester.
Stephensons' Manchester team specialises in family law and criminal cases but also includes experts in residential conveyancing and commercial and corporate law. The firm has offices in Altrincham, Bolton, Leigh, St Helens and Wigan.
Mike Devlin, managing partner, said: "We're looking forward to moving into new offices, which are fit for modern open plan working and will also enhance our clients experience when they come to see us. We are committed to expanding our services in Manchester and the surrounds and have developed a first class, award-winning family law service over many years in the city. Being close to our clients and the court was therefore an important part of our decision when selecting our new home."
Deva landlord Highcross was advised by joint letting agents CBRE, Canning O'Neill and Edwards & Co.