Big Lagoon

Big Lagoon is an estuarine lagoon in Escambia County, Florida, about 10 miles southwest of Pensacola. It separates the eastern part of Perdido Key from the Florida mainland and extends east toward Pensacola Bay. The Gulf Intracoastal Waterway runs through it. The Pensacola & Perdido Bays Estuary Program counts Big Lagoon as part of the Pensacola Bay system. Big Lagoon State Park, a 706.76-acre state park first acquired in 1977, covers the northern shore. Most of Perdido Key on the south side lies within Gulf Islands National Seashore. All waters within the state park have been designated Outstanding Florida Waters, and the park is adjacent to Fort Pickens Aquatic Preserve.

The Florida Department of Environmental Protection's Division of Recreation and Parks runs the Big Lagoon State Park boat ramp, which gives access to the Intracoastal Waterway. The park's kayak launch at East Beach opens left into a marsh slough leading to Grande Lagoon, or right onto the Intracoastal Waterway toward Johnson Beach on Perdido Key. The Florida Circumnavigational Saltwater Paddling Trail, 1,515 miles long, begins here. The 2018 park management plan states that most of the Intracoastal Waterway south of the park is a no-wake zone. It also notes that buoys once marking motor exclusion areas over seagrass beds and mud flats were lost in storms and had not been replaced. Hurricane Sally damaged park boardwalks and pavilions in 2020, and the park fully reopened on July 7, 2023.

Woodland-period shell middens within the park point to past use of the lagoon for gathering shellfish. Manatees are occasionally seen in waters next to the park.