The deal forms part of a wider £44m plan to build a 140,000 sq ft superstore for Tesco on the 50-acre former United Glass site.
During construction, the Saints will play their home matches at Widnes Vikings’ Halton Stadium.
Taylor Wimpey will build 100 homes and 90 apartments at the existing St Helens Rugby League Club site at Knowsley Road.
Saints chairman Eamonn McManus said: “The building contractor for our new stadium, Barr Construction, has been appointed and remediation and construction work will start shortly.”