Being brought forward under the hub South West Scotland partnership, the school will accommodate over 900 pupils, with the build taking place on the existing site.
The hub South West team includes Morgan Sindall Construction and Ryder Architecture leading the design.
Turner & Townsend is delivering cost management, project management with Woolgar Hunter leading on civil and structural engineering elements of the new school.
The new school will include new sports accommodation to replace the existing David Keswick Athletics Centre. The new school is expected to be completed by Summer 2025.
Stuart Parker, managing director at Morgan Sindall Construction Scotland, said work would now start before the end of the year.