© WCTE 2018 Committee. The structural performance of innovative single and double skin timber-filled steel columns is experimentally investigated in this paper. Thin-walled steel rectangular hollow sections are filled with sawn sections of timber lumbers of low moisture content. The timber is then allowed to absorb moisture at ambient temperature and humidity. Its expansion is restrained by the steel tube, eventually creating friction between the two materials and thus generating composite action without the use of glue or mechanical fasteners. The manufacturing procedure is therefore simple and cost-effective. Single skin and double skin timber-filled tubular steel (TFTS) stub columns were manufactured and tested in compression in this paper. Effect of timber properties on structural response of TFTS stub columns is investigated using experimental tests and a proposed analytical solution that captures the experimental force-displacement response with good accuracy. It is understood that single skin TFTS stub columns with low-quality timber show more ductile response when compared to those with high-quality timber inserts. The ultimate axial compressive strengths of TFTS stub columns are shown to be highly sensitive to the Modulus of Elasticity (MOE) and yield stress of the timber inserts and less dependent to its post-yield properties.