£100,000 has been given to the Beacon Arts centre which is currently under construction, due to open next year.
The building is going to consist of a 500 seat auditorium and a 130-seat studio theatre.
There will also be rehearsal rooms and a cafe overlooking the River Clyde.
The theatre in total will have cost £9.5million which replaces the Greenock Arts Guild theatre which has served its town for 60 years.
Guild chairman Elliott McKelvie said: "We are delighted that The Andrew Lloyd Webber Foundation shares our vision of the important role which the arts and arts-education can play in helping to improve people's lives.
