Overconsumption of fat leads to cardiovascular diseases and other health problems; therefore, consumers prefer diets with high fiber and low fat content for their healthy weight management. Fat replacers can be potentially applied in several foods but they can affect appearance, texture, rheology, and flavor of emulsion products. This research aimed to study the effect of oatmeal as a fat replacer on creamy salad dressing (53.39%(w/w) refined soybean oil, 20.20%(w/w) sweetened condensed milk, 12.99% (w/w) distilled vinegar, 8.08%(w/w) egg yolk, 4.33%(w/w) refined sugar, 0.58%(w/w) iodized salt, and 0.43%(w/w) mustard). The oatmeal was used to partially replace soybean oil in the product at 3.61, 7.22, 10.82, 14.43, 18.04, and 21.65%(w/w). After preparation, fat content, protein content, apparent viscosity, and sensory acceptance of control and fat-reduced samples were evaluated. Fat replacing with oatmeal led to decreasing of fat content but increasing of protein content and apparent viscosity. At 21.65% fat replacement, there was 33.13% fat reduction compared to the control sample. In sensory evaluation by 30 untrained panelists, reduced-fat creamy salad dressing had the same or higher acceptance scores in appearance, color, texture, aftertaste, and overall acceptance. Oatmeal can be an alternative fat replacer in reduced-fat creamy salad dressing.