Arroyo Acaraguá is a river in the province of Misiones, Argentina, measuring 81.5 km in length and draining a watershed of approximately 805 km². It originates at an elevation of 358 meters in the Sierra de Misiones, formed by the confluence of the Acaraguá Primero and Acaraguá Segundo streams roughly 2.5 kilometers southeast of Campo Grande, in the department of Cainguás, near Ruta Nacional 14. From there it flows generally eastward, eventually emptying into the Río Uruguay near the locality of Barra Bonita at an elevation of 105 meters, giving the river a total drop of around 253 meters over its course.

Downstream from its headwaters, the Acaraguá forms the boundary between the departments of Oberá and Veinticinco de Mayo. Tributaries entering from the right bank are notably more substantial than those on the left, which in some stretches measure less than 2 kilometers. The principal tributary is the arroyo del Medio, with other right-bank streams including the Nambú, Francés, Mirí, and Apepú also contributing to the flow.

The river's name derives from Guaraní: "acara" refers to the heron, and "gua" denotes a place where a particular animal or plant is abundant, making the name roughly translatable as "place where herons abound."

Kayaking activity has been documented on the Acaraguá, with Club Náutico Acaraguá operating in the area near Campo Ramón, suggesting organized paddling infrastructure exists along at least part of the river's course. Aerial footage has also been recorded at a location known as Picada Argentina along the arroyo. Paddlers planning a trip should seek current local information from the Club Náutico Acaraguá or regional tourism operators in Campo Ramón before putting in.