A comprehensive experimental study is carried out on the compressive behaviour of high strength innovative hollow columns. In terms of geometric appearance, the innovative square section of columns is the produced by welding steel tubes with nominal diameter-to-thickness ratio of 23.78 to mild steel plates with a nominal width-to-thickness ratio of 70. The tubes are of three types of mild, high strength (HS) and ultra-high strength (UHS) steel with nominal tensile strength of 890MPa and 1380MPa, respectively. The connection of high strength tubes to the sides of plates causes a satisfactory increase in the ductility and improves local buckling behaviour of each mild steel plate whilst the restraint provided by plates enhances the resistance of each tube against global buckling. This effective interaction between the elements leads to taking advantage of the high strength of tubes and, simultaneously, keeping the weight of the section as low as possible. Experimental outcomes of steel columns containing tubes are compared with similar columns without tubes, showing a significant increase in the peak compressive load and ductility.