The £3.4m enabling works signals the go-ahead for the latest scheme to be delivered under the Band B, Sustainable Communities for Learning programme.
Morgan Sindall will also take the design of the main school forward, under a pre -services contract.
The secondary school project will see the existing school relocated and rebuilt on land off Lewis Road, Splott.
Subject to planning and procurement, construction of the new campus is expected to start this Autumn.
The new school will offer comprehensive sports facilities, including sports hall, gym, drama studio and grass pitches which will be available for public use outside school hours.
Rob Williams, Area Director at Morgan Sindall Construction, said: “It’s a real privilege to be awarded the contract for the enabling works at Willows High School in the vibrant city of Cardiff, which will pave the way for a 900-place secondary school.“
