A detergent dispenser module for a dishwashing appliance may generally include a body extending between a top side and a bottom side. The body may include an outer surface extending from the top side and may define a detergent chamber between the outer surface and the bottom side. The detergent chamber may be at least partially formed by an upper sidewall, a lower sidewall and a bottom wall extending between the upper and lower sidewall. In addition, the dispenser module may also include at least one flow diverter extending outwardly from the outer surface at a location adjacent to the upper sidewall of the detergent chamber. The flow diverter(s) may be angled in a direction of a fluid collection opening defined through a top of the upper sidewall such that fluid flowing downwardly along the outer surface of the body is directed into the fluid collection opening.