Grafting carbon nanotubes (CNTs) onto reinforcing fibre surfaces has been shown to improve composite structural performance, through improved interfacial bonding of the matrix and reinforcement. Sourcing a suitable amount of CNT-grafted fibre has currently limited test coupons geometry and development in the area. The scale-up of current synthesis procedures for grafting CNTs onto carbon fibre (CF) surfaces, using low intensity processing techniques (minimal processing of fibre substrate) compatible with industrial practices has not yet been reported. CNT growth from CF surface (CNT-g-CF) without damaging the mechanical parent fibre properties is a challenge as chemical vapour deposition (CVD) CNT growth typically results in catalyst pitting and surface defects occurring. In this thesis I attempt to address concerns detailed above; through the development of a catalyst system which is easily deposited onto CF, uses a CVD CNT-synthesis method which does not damage the original fibre properties in a potentially continuous scalable manner. I present a simple incipient wetness technique for loading a bi-catalyst precursor mixture onto CF. CF pre-deposited with bi-catalyst precursor under the application of an electric field, using CF as an electrode, in-situ during conventional thermal-CVD demonstrated significant promotion of CNT-synthesis directly from the CF surface. Electric field applied during CVD CNT-synthesis produces CNT-g-CF without apparent mechanical degradation to the parent fibre retaining original mechanical properties. When CVD CNT-synthesis is undertaken without the application of an electric field, degradation of original mechanical properties are witnessed. Batch CVD process was adapted, in an attempt to demonstrate the feasibility of continuous production of CNT-g-CF in a bespoke continuous CVD set-up. Alternative routes for CNT-g-CF including a novel silicon oxide based CNT-synthesis are also discussed.