<p>In this study, the dissolution of hemp–wool blend yarns in the ionic liquid (IL) 1-ethyl-3-methylimidazolium acetate [Emim][OAc] has been investigated. The hybrid yarns were dissolved in excess IL at various temperatures and times, followed by coagulation in water. Optical microscopy (OM), gravimetric analysis and wide-angle X-ray diffraction (XRD) were used to monitor structural changes of the two components separately during the dissolution and subsequent coagulation. All results showed that the hemp cellulose fraction dissolved faster than the wool keratin part, this being due to the additional strong disulfide bonds in the keratin (wool) fibres and the complex hierarchical structure of keratin. The increase in the cellulose dissolved fraction, which remained after coagulation in water, was measured by XRD and was found to follow time–temperature superposition (TTS) with an Arrhenius behaviour, giving an activation energy for cellulose dissolution of <i>E</i>_a = 55 ± 5&#xa0;kJ/mol. Analysis of the optical images and the gravimetric analysis showed that both the cross-sectional area (<i>A</i>) and the mass per unit length decreased with time and temperature. They both followed (TTS) and gave activation energies of <i>E</i>_a = 112 ± 11&#xa0;kJ/mol and 109 ± 6&#xa0;kJ/mol, respectively, leading to an average value of 111 ± 9&#xa0;kJ/mol. We propose that this is the activation energy for the dissolution of the keratin fraction of the hybrid yarn in [Emim][OAc], as we attribute the mass loss (and decrease in the cross-sectional area) of the hybrid yarns to the loss of the keratin fraction, which is removed during the coagulation phase. To the best of our knowledge, this is the first study to apply TTS to a cellulose–keratin hybrid system and deconvolute the dissolution behaviour of each component through the characterisation and analysis, providing new insight into the dissolution dynamics of blended biopolymers in ionic liquids.</p>