The purpose of this study was to differentiate between muscular activity of three different types of belt squats (SquatMax-MD, Pit Shark and Monster Rhino) and the muscle activation of the rectus femoris, vastus medialis oblique, gluteus maximus, and gluteus medius. Fourteen healthy, male athletes, over the age of 18 years, performed 2 sets of 5 repetitions on each of the three belt squat machines with a weight equivalent to each participant’s body weight. Athletes were given at least 2 minutes of rest between each set and condition. Electromyographic data were collected from four muscles: rectus femoris, vastus medialis oblique, gluteus maximus, and gluteus medius muscles. ANOVA revealed the SquatMax-MD belt squat resulted in the highest muscle activation in every muscle, with significantly higher activity in the rectus femoris, vastus medialis oblique, and gluteus medius muscles. The Monster Rhino belt squat produced the second highest muscle activation with the Pit Shark belt squat creating the lowest muscle activation. In totality, the SquatMax-MD produced 38.7% greater muscle activation than the Monster Rhino and 12.2% greater activation than the Pit Shark. The belt squat can be an advantageous exercise because it can effectively load the lower body while de-loading the spine and upper body. The difference in activation between the SquatMax-MD and other belt squats may be due, in part, to the design of the machines. The additional activation produced by the SquatMax-MD belt squat may be useful for individuals seeking hypertrophy, strength, or a reduction in injury risk.