The tomato processing industry produces waste products that are not utilized and add to the problem of environmental pollution. Tomato peel still contains high bioactive components, tomatoes as the main source of beta-carotene and lycopene are expected to improve food quality. Owned antioxidant activity can reduce the oxidation process in food products. Low-fat mayonnaise is a type of low-fat mayonnaise that has a fat content of less than 40%. The purpose of this study was to investigate the effect of adding tomato peel nanopowder to low-fat mayonnaise based on emulsion stability, viscosity, moisture content, fat content, antioxidant activity, and fatty acid profile. Low-fat mayonnaise was prepared using sunflower oil, vinegar, and egg yolk by giving 1%, 2%, and 3% tomato peels nanopowder treatment, and without the addition of control which was repeated 5 times. A completely randomized design was used as the research design. Analysis of variance was used as statistical analysis and continued with Duncan's test if there were significant or very significant differences. The results of the study adding nanopowder tomato peel with different percentages had a very significant effect (p<0.01) on emulsion stability, viscosity, water content, fat content, antioxidant activity, and the presence of various types of fatty acids in low-fat mayonnaise. The addition of tomato peel nanopowder can increase the stability of the emulsion, viscosity, and antioxidants, as well as reduce the water content and fat content. This study concludes that 3% tomato peel nanopowder is capable of being a natural antioxidant that can improve the physicochemical quality of low-fat mayonnaise.