A lateral intake, also known as a side intake or side channel intake, is a structure designed to divert water from a main channel or stream into a secondary channel or conduit for various purposes such as irrigation, water supply, or drainage. It is often used for discharge withdrawal in hydropower engineering. The coefficient of discharge plays a crucial role in determining the actual water flow rate through the hydraulic intake system. Most past research focused on figuring out the discharge coefficient in open channels for various orifice shapes and circular intakes. A thorough literature assessment reveals that few studies are available to compute discharge coefficients for square intakes. This paper deals with the experimental investigation of discharge characteristics of square intakes in open channels under a uniform approach flow. For the experiments, a concrete channel of length 9.47 m, width 0.5 m, and a depth of 0.6 m was adopted. The discharge characteristics of lateral intake were studied by placing an intake pipe of 0.04 m × 0.04 m, 6.0 m upstream. The data analysis indicates that the approach Froude number (Fr), intake Froude number (Fri), and intake Reynolds number (Rei) have a significant influence on the coefficient of discharge (Cd) for the square intakes. The results show that, when other factors such as bottom clearance, channel width, and main channel discharge are kept constant, the Cd decreases with increases in Fr, Fri, and Rei.