Fat replacers in food products can significantly affect their texture and rheological behavior. One reason for this effect is changes to food–saliva interaction. These changes are not always reflected in standard rheometry. Therefore, the objective of this study was to determine the impact of saliva addition on the rheological and tribological behaviors of acid milk gels. Samples (24 total) were prepared by mixing skim milk with various amount of fat (0–3.5% wt/wt), skim milk powder (SMP, 0–2.8% wt/wt), sweet whey protein isolate (WPI, 0–2.8% wt/wt), and hydrocolloids (locust bean gum (LBG), cellulose gum, potato and corn starch, 0–1.55% wt/wt). SMP and WPI were added to adjust protein and solid nonfat. The mix was pasteurized at 85°C for 30 min, then homogenized at 5000 RPM for 1 min. The mix was cooled to 42.2°C, then glucono-delta-lactone (GDL, 1.2–1.6% wt/wt) was added to slowly acidify the mix over a 4 h incubation at 42°C (final pH of 4.55–4.60). The gel was broken at the appropriate pH and refrigerated overnight. Shear rate sweeps, strain sweeps, and frequency sweeps were done at 8°C and 25°C to evaluate flow and viscoelastic properties. Tribological testing (0.01–600 mm s⁻¹ sliding speed, 1 N normal force) was also performed at 25°C. All samples were tested with and without human whole saliva (1:6 ratio of saliva: sample). Two-tailed t-tests and a 2-way ANOVA were performed to assess the temperature, saliva and hydrocolloids effects. Most samples showed viscoelastic solid behavior and all samples showed shear-thinning behavior. Sample viscosity and viscoelastic moduli decreased with added saliva, increased temperature, or both but changes were not significant for samples with added saliva. Most samples tested with saliva showed lower friction coefficients than samples tested without saliva. Hydrocolloid type and amount highly affected acid milk gel strength and stability. LBG and potato starch made stronger gels than corn starch and cellulose gum. This information on the impact of saliva on acid milk gels with various components will allow targeted formulation of yogurt with desirable textures.