This study aims to investigate coastal morphodynamics and geological evolution during the last 800 years in a coastal wetland behind Bay Champagne near Port Fourchon, Louisiana. Multi-proxy analyses (losson-ignition, X-ray fluorescence, and principal component analyses) were conducted on a 200cm sediment core retrieved from a small pond on a mangrove-dominated island. The study area has experienced significant morphodynamic and geological changes due to delta-lobe switching, relative sea level rise, and hurricane events over the last 800 years. An increase in sediment supply and fluvial processes led to the development of marsh ~ 600cal yr BP during the Bayou Lafourche delta progradation, marked by elevated terrestrial elements (K, Ti, Zr). After that, land subsidence and sea level rise accelerated saline water incursion and coastal retreat after the abandonment of the Bayou Lafourche delta ~ 100cal yr BP, marked by elevated marine concentrations (Ca, Sr).