The roof of the church, which collapsed in 2010, was restored after the Danish Ministry of Culture generously donated funds to restore the piece of architecture.
The restoration work began in 2013 and following the Rs 3 crore restoration, the church property is now ready to be reopened to the public later this week, Bishop Ashoke Biswas said.
St Olav's Church was built in 1806 during the time when Serampore was a flourishing trading town under Danish administration. Serampore is around 30 km from Kolkata.
The original doors, windows and furniture were restored while flooring was relaid with sandstone from Rajasthan.
Lime mortars and organic pigments were used on all walls, following the original colour scheme established through a scientific paint analysis, said Dr Bente Wolff of the National Museum of Denmark.
She said a new roof was laid using the traditional water-proofing technique of compacting lime concrete through weeks of continuous beating.