Synthetic azo dyes are economic, cheap and stable to washing and sunlight exposure due to their chemical structure and properties. For such reasons, these dyes are extensively used in coloring of textile, leather, plastic and paint but they can cause quality damage to the water bodies which make it necessary to treat the dyes before discharging into the environment as they have great potential to negatively affect the environment. This research addressed the theory and the effects of operational parameters involved in Sono-Fenton oxidation on the targeted pollutant (Congo red). The effects of varying the concentrations of hydrogen peroxide and iron sulfate, pH, ultrasonic power, dye concentration, temperature and reaction time on the discoloration and degradation efficiencies were investigated. Degradation was carried out with Ultrasonic frequency of 35 kHz at 20, 40, 60 and 80 W acoustic intensity with initial dye concentration of 5, 10, 15, 20, 25, and 50 mg L^-1 and optimized quantities of H₂O₂ and FeSO₄ addition. It was observed that the degradation rate by Ultrasound alone was slow, however, sonication significantly accelerated the Fenton reaction. Alone Fenton process resulted in less removal of the dye from the solution, but Ultrasound assisted Fenton technique maximized the results upto 83 % in 60 min and COD was removed up to 89% from the solution after 60 min of contact time. From the derived results it is concluded that Ultrasound can significantly increase the degradation rate of Congo red dye in a solution through Ultrasound assisted Fenton process as they produce rather more H•  and •OH radicals synergistically which enhances the degradation efficiency.