The effect of creating parallel welds in a single overlap using continuous ultrasonic welding on the weld quality has been investigated, with the goal of creating three high-quality parallel welds. To achieve this, multiple aspects were examined to understand the creation of high-quality parallel welds. The weld quality is highly influenced by a change in boundary conditions. The number of welds, the order of welding, and the energy director strategy all change the boundary conditions. Increasing the number of parallel welds will make it more difficult to create high-quality welds. The order of welding has a large effect on the quality of the welds. The order of welding will determine if a low- or high-quality weld is created with constant welding parameters. Two energy director strategies were compared: a ‘full overlap energy director’ and ‘energy director strips’. Both can create high-quality welds, but energy director strips create an overall better-quality weld.