ABSTRACT This research examines the interfacial bond strength of metakaolin‐based geopolymer mortar across two key connections: flexural mortar–mortar and steel–mortar. It investigates the effect of interfacial roughness and curing age on the bond behavior of metakaolin‐based geopolymer mortar (GPM) and cement‐based mortar (CM). In this research, the mortar‐to‐mortar bond strength was assessed using the flexural three‐point bending test on smooth and grooved interfaces after 28 + 7 and 28 + 28 days of curing, complementing previous slant shear and split tensile test results. For the steel–mortar investigation, push‐in tests were conducted on 10 mm diameter ribbed and 8 mm diameter smooth steel reinforcing bars, with 7 and 28 days of curing for each. Additional tests included compressive strength, ultrasonic pulse velocity, and drying shrinkage, alongside previous bond strength research using the slant shear and split tensile tests. Results demonstrate that geopolymer mortar achieves superior bond strength compared to cement mortar, with bond strengths more than double that of cement mortar. Geopolymer mortar also attained faster bond strength on grooved surfaces. Similarly, the steel–mortar bond strength of metakaolin‐based geopolymer mortar was approximately four times greater than that of cement mortar with ribbed rebars, although results were closer with smooth rebars. These findings highlight the potential of metakaolin‐based geopolymer mortar to enhance bond performance while reducing environmental impact, presenting a promising avenue for sustainable construction practices.