The theatre closed in July for the work to be carried out
Bath Theatre Royal will reopen on Tuesday following a £3m refurbishment to upgrade the Main House.
The 205-year-old Grade II* theatre closed in July for the work which included extending and remodelling the foyer.
The theatre's disabled access was also upgraded during the work and new bars were installed.
The main house will reopen with a performance of The Rivals starring Penelope Keith and Peter Bowles.
Derek Quinn, from Midas, the firm that carried out the work, said the short timeframe added extra pressure.
"Working on cherished buildings of historic significance will always pose a challenge and in the case of the Theatre Royal Bath, this was made all the more difficult as we only had a two month period of complete closure to undertake the work.
"We are especially proud to be associated with a theatre which is known throughout the world and to play a part in really improving a significant part of our national heritage."