<p>The objective of this study was to investigate structural and rheological properties of fish gelatin (FG)/κ-carrageenan (κ-CG)/sodium alginate (SA) ternary mixtures. Different ratios of FG/κ-CG (3.2%/0.5%, 2.8%/0.9%, 2.4%/1.3%, and 2.0%/1.7%, w/w) were mixed with a stock solution of SA (0.3%, w/w) to produce FG/κ-CG/SA ternary mixtures. Based on field emission-SEM images, the ternary mixture at FG/κ-CG (2.0%/1.7%) exhibited a smoother surface and a more compact internal structure as the concentration of κ-CG increased. This enhancement in the morphology of the ternary mixture is attributed to the interaction between FG and SA, which was further supported by XRD and FT-IR analysis. Specifically, the presence of κ-CG facilitated the interaction between FG and SA, leading to a more cohesive and stable structure. FG/κ-CG/SA-3.2%/0.5%/0.3% had the lowest consistency index (K) and apparent viscosity (η_a,100). However, the highest values in K and ηa,₁₀₀ were observed for FG/κ-CG/SA-2.0%/1.7%/0.3%, indicating that the synergistic interactions of ternary mixtures were enhanced by increasing the concentrations of κ-CG in the ternary mixtures. The dynamic modulus of ternary mixtures increased with an elevation in the concentrations of κ-CG. These results suggested that the structural and rheological properties of FG/κ-CG/SA ternary mixtures can be strongly influenced by the concentration of κ-CG.</p>