The main sources of dietary carbohydrates worldwide are cereals and legumes, which are predominantly composed of starch. The aim of this study was to extract quinoa starch using three different methods—wet milling, enzymatic treatment, and ultrasound—and to compare their physicochemical properties. The results indicated that the extraction method had significant effects on turbidity, swelling power, and viscosity. However, due to the use of a single quinoa variety, no significant differences were observed in starch extraction yield, solubility, amylose content, or refrigeration and freeze–thaw stability among the methods. The highest solubility (15.5%) and the greatest swelling power (10.18 g/g) were obtained in the ultrasound treatment (30 min). In addition, the highest turbidity was recorded for the enzymatic method (3.19%), while the lowest value belonged to the ultrasound treatment (2.33%). The viscosity of starch extracted by the wet milling method was higher than that of the other methods, whereas the ultrasound-extracted starch showed the lowest viscosity. Scanning electron microscopy (SEM) images revealed that the extraction method had no notable effect on starch granule morphology, and all samples exhibited polygonal granules with an approximate size range of 1.5 to 4.5 µm.