The Grade II*-listed venue in Graces Alley, near Tower Bridge, is undergoing a project to restore the main Music Hall.
Closed since July 2012, the auditorium will reopen next month following work to improve access, install effective heating and ventilation, and repair walls, roofs, windows and doors.
Originally an alehouse dating from 1743, Wilton’s now comprises a mid-19th century grand music hall attached to an 18th century terrace of three houses and a pub.
Corporate events at the venue have included Smirnoff, as well as smaller meetings.
Following the first phase of renovation, it is hoped that a £2.2m second phase can begin in spring 2014, following a Heritage Lottery Fund (HLF) grant application.
Wilton’s development director Kate Mitchell explained the second phase would include renovations to the Georgian houses at the front of the building, as well as opening up the currently unused top floor.
"By opening up the top floor we can create educational studios, which could be used for events activity," added Mitchell.