Texture plays a key role in consumer acceptance of semisolid foods such as yogurt. Hydrocolloids can significantly alter semisolid food structure, which affects their texture. Additionally, semisolid foods show different oral behaviors as a result of interactions with saliva. A better understanding of how different hydrocolloids and saliva interactions affect semisolid food textures could help in the development of low-fat or fat-free products with textures similar to their full-fat counterparts. Thus, the objective of this study was to determine the effect of saliva and hydrocolloids on rheological and tribological behaviors of yogurts. Twelve different yogurt formulations were prepared with skim milk, skim milk powder (0–2.8% wt/wt), cream (0–3.5% wt/wt), whey protein isolate (0–2.8% wt/wt), and hydrocolloids (corn starch, potato starch, locust bean gum and cellulose gum; 0–1.55% wt/wt). Yogurt mixtures were pasteurized at 85°C for 30 min, homogenized at 5,000 rpm for 1 min, and cooled to 42.2°C for the addition of starter cultures. The mix was incubated for 5–6 h to reach a pH of 4.55–4.6, and then the gel was broken and refrigerated overnight at 4°C. Tribometry was performed at 25°C and rheometry (shear rate, strain, and frequency sweeps) was performed at 8°C and 25°C. Both rheometry and tribometry were conducted with and without human whole saliva. Two-way ANOVA was used to analyze rheological data; one-way ANOVA was used for tribological data. Addition of saliva caused significant differences in viscosity at 1 s⁻¹ and friction coefficient at 0.1 mm s⁻¹. Critical strains with and without saliva were not significantly different. Most samples showed solid-like behavior; the highest storage moduli were for the sample containing WPI alone. Control samples had the lowest viscosity; the addition of hydrocolloids and WPI significantly increased viscosity. In general, friction coefficient decreased with added saliva. Confocal images showed a distinct, heterogeneous protein network with longer clusters and fat coalescence for samples with added saliva and hydrocolloids. These results can help manufacturers design low-fat semisolid foods with similar textures to their full-fat counterparts.