Roselle calyces, which contain natural red pigment, anthocyanin, can be utilized as natural colorant and antioxidant source in ice cream. Its red color exhibition and stability can be improved by the addition of citric acid. However, their addition is limited due to the acidic and bitter aftertaste they imparted. This research was carried out to develop functional ice cream product with natural colorant derived from roselle calyces with the optimum set of roselle calyces extract and citric acid levels. Response surface methodology (RSM) was employed to analyze the effect of different concentrations of roselle calyces extract and citric acid on the physico-chemical characteristics and consumer sensory acceptance of ice cream. A central composite design consisting of two independent variables (roselle calyces extract and citric acid levels) in a five levels pattern (-1.41421, -1, 0, +1, and + 1.41421) with 13 runs (formulations) was prepared. This design was used to establish the optimum set of variables to maximize the consumer sensory acceptance of ice cream. Higher concentration of roselle calyces extract significantly increased the total anthocyanin content and color acceptance, while decreased the °Hue and pH of ice cream. Higher concentration of citric acid significantly increased the overrun and color acceptance, but decreased the viscosity, °Hue, pH, texture, taste acceptance, and overall acceptance of ice cream. The maximum scores of consumer sensory acceptance were met at 11.5% roselle and 1.5% citric acid levels.