Acoustic Enclosure for Steam Turbine comprises of collapsible type acoustic wall and roof panels, assembled on bolted structure. The Acoustic Enclosure is provided with soundproof doors and glass windows in adequate numbers. The Acoustic Enclosure is facilitated with forced ventilation package with ventilation exhaust blower, ventilation intake silencer and ventilation exhaust silencer, to take away the heat built up inside the enclosure. Acoustic Enclosure for Steam Turbine has provisions for electrical and fire fighting system.