In concrete-filled steel tubular (CFST) columns, the load is introduced through axial compression and beam shear connections, typically realized by welding or blind-bolting open-section beams to closed-section CFST columns. For non-compact and slender sections, the bond behaviour at the steel-concrete interface proves insufficient for complete load transfer and the realisation of composite action. Therefore, in this study, the composite behaviour of the non-compact CFST column was investigated with welded and blind-bolted shear connections. Different lengths above the connection were considered to explore the effects of column length above the connection on the composite action of non-compact CFST columns. For the blind-bolted shear connections, standard hollo bolts and extended hollo bolts were used for the connection fabrication. From the study, it has been primarily observed that welded specimens cannot achieve full cross-sectional strength, even with longer column length above the connection. However, for specimens with both standard and extended blind-bolted connections, an enhanced composite action could be achieved compared with their welded shear connection counterparts, especially for the extended blind bolts. This could be attributed to that the shear load was effectively transmitted to the infill concrete via bolt bearing, ensuring complete load introduction without over-dependency on the steel tube-to-concrete interfacial bond.