Laguna Setúbal, also known as Laguna de Guadalupe, is a large shallow lagoon situated on the eastern edge of the city of Santa Fe, in Santa Fe Province, Argentina. It covers approximately 32 square kilometers with a shoreline of around 27 kilometers, a mean depth of 3 meters, and a maximum depth of 28 meters in areas that were dredged for flood-control and urban infrastructure works. The lagoon sits at an elevation of 10 meters above sea level and is part of the floodplain of the río Paraná, draining through the Riacho Santa Fe. Its water level can fluctuate by as much as 9.5 meters annually, which is a critical planning consideration for paddlers — shallow or low-water periods can make crossing on foot tempting but dangerous, and access points may change significantly with water level.

The lagoon is fed permanently by the Arroyo Leyes and Arroyo Potreros, and semi-permanently by the Saladillo Dulce and Saladillo Amargo. The water is characteristically brown, typical of Paraná delta systems. The lagoon is crossed by the Viaducto Oroño and the Puente Colgante, the latter being a prominent landmark along the Costanera Este waterfront.

For paddlers, kayak and SUP rentals are available at beach parador facilities along the Costanera Este. The Prefectura Naval patrols the waterways in the area to enforce maritime safety regulations. Kitesurf is also practiced on the lagoon, so paddlers should be aware of other water users, particularly in the open sections near the Costanera. The lagoon connects northward to the laguna Leyes (also called laguna Santo Domingo) and laguna San Pedro or Capón, offering potential for extended exploration.

The surrounding delta islands contain internal arroyos and interior lagoons where irupé water lilies grow, and the area supports a notable variety of birdlife, including flamingos during low-water periods.

The lagoon is a public natural area with no entrance fee. Sunsets viewed from the Costanera over the water are widely regarded as a highlight of the paddling experience here. The lagoon also serves as a source of drinking water for the city of Santa Fe, so awareness of water quality and responsible behavior on the water is particularly relevant.