The Three Gorges Dam Project (TGP) on the Yangtze River is the world's largest hydropower complex project. Dongting Lake is the first large lake downstream of the TGP, and substantial changes have been noted in the hydrological regimes, water quality, and wetland environments since the TGP began operation. This review summarizes the influence of the TGP on Dongting Lake based on the reservoir dispatch scheme, interaction between the river and lake, and vegetation distribution patterns of lake wetlands. The TGP reduced the sediment discharge from the Yangtze River to Dongting Lake and slowed the sediment deposition rate. This was beneficial for the lake in the short term because it increased water regulation space and extended the life of Dongting Lake. The TGP reduced water inflow from upstream and changed the variation pattern in water level. The TGP exerted direct and indirect effects on water quality of Dongting Lake. There are still controversies regarding water quality impacts of the TGP operation on Dongting Lake, and the TGP has exacerbated pollution in some regions. Reduced water level variation and sedimentation have jointly changed the process of vegetation succession in Dongting Lake. The succession rate becomes slow, and the vegetation succession sequence is aquatic plants, Phalaris arundinacea or Carex sp., Phragmites australis, and ligneous plants. Trends and directions of future research on these subjects are discussed. This study will provide a reference for further studies on the relationships between Dongting Lake and the TGP.