This study aimed to analytically develop tensile stress-crack width constitutive relationships for hybrid fibre reinforced concrete (HFRC). An inverse analysis was performed based on the fictitious crack hinge model to derive the stress-crack width relationship through careful calibrations of model parameters with the digital image correlation (DIC) measurements. The studied parameters included fibre types, volume fraction (Vf) and their combinations. Multilinear stress-crack width relationships for steel, polyolefin and hybrid fibre reinforced concrete with three different fibre volume fractions of 0.50%, 0.75% and 1.00% were derived. The hinge parameters assumed in the inverse analysis were validated with the help of full-field strain measurements using the DIC technique. The relationship between the crack tip opening displacement (CTOD) and the crack mouth opening displacement (CMOD) was verified with the help of the developed equations through the inverse analysis. Afterwards, the simplified equations for predicting the stress-crack width relationships for various types of hybrid FRC were proposed. © 2020 Elsevier Ltd