Behaviour of GFRP bar reinforced HSC (GFRP-HSC) columns is investigated. Behaviour of GFRP bar reinforced steel fibre HSC (GFRP-SFHSC) columns is reported. Axial load-bending moment (P-M) interactions of GFRP-HSC columns are presented. Axial load-bending moment interactions of GFRP-SFHSC columns are also presented. Procedure of establishing analytical P-M interaction diagrams is proposed.