Grand Bayou is an unincorporated Native American community in Plaquemines Parish, Louisiana.

The coastal village is home to the Atakapa Ishak Chawasha tribe and is only accessible by water.

Grand Bayou received increased attention after the Louisiana Coastal Protection and Restoration Authority's 2017 master plan for coastal restoration included neither aid nor a resettlement plan for the village.

[3][5] In 2024, a 600-acre parcel (240 ha) that includes a sacred mound was given back to the tribe by St. Paul's Episcopal Church of New Orleans.

[6] The church's ownership was discovered when the tribe was working with the Coalition To Restore Coastal Louisiana on shoreline protection.