Pupils will get to see the excellent new facilities when the new term starts on Tuesday 14 April, after the council has invested £35million to rebuild the wing.
Over 60% of St Kentigern's had to be demolished due to issues with Reinforced Autoclaved Aerated Concrete (RAAC). St. Kentigern's is one of the the area's largest schools, and serves pupils from towns and villages across the west of West Lothian.
Interim Depute Chief Executive Greg Welsh said: "It's fantastic to have the superb new replacement wing at St Kentigern's Academy completed as planned.
"This will allow pupils to sit all their SQA exams in school for the first time in three years, and all subject areas will now be delivered from within the school going forward.
"The excellent new facilities will make a real positive difference to the learning experience of St Kentigern's pupils for many years to come.
"Special thanks go to the St Kentigern's community for their understanding and support during construction period, including school staff, parents/carers and especially our amazing young people.
"Our appreciation also goes to everyone who worked tirelessly to deliver this essential project in such a short timescale, including our development partner Hub South East, main contractor Heron Bros, BDP Architects, and colleagues from a range of services across the council."
The new building features a reception area, spacious canteen and dining area, a four-court Games Hall, Dance Studio, Fitness Suite and a changing village.
It also includes a performance area, a range of learning spaces, a café and nurture rooms, all designed to enhance the learning environment for all of the young people who attend the school.
