The Atlantic Multidecadal Variability (AMV) refers to multidecadal (60~80 year) quasi‐oscillation in North Atlantic sea surface temperatures. The AMV has significant impacts on global and regional climate. However, the fundamental physical mechanisms and processes underlying the AMV remain a hot research topic. Internal ocean dynamics, atmospheric stochastic forcing, and external forcings of either anthropogenic or natural origins all have contributed to the AMV. Improved knowledge of the AMV is of great scientific importance for understanding the causes of global climate change as well as for decadal climate predictions. This paper reviews the definition and main characteristics of the AMV, its underlying mechanisms and climate impacts. This study also discusses the key topics and outstanding issues in AMV research.