Abstract Fjords have long been recognized for their value as sites of sediment deposition, recording past climatic conditions. Recently, Arctic fjords have been recognized as the critical gateway through which oceanic waters can impact on the stability of glaciers. Arctic fjords are also used as idealized locations to study ice-influenced physical, biological and geochemical processes. In all cases a clear understanding of the physical oceanographic environment is required to interpret and predict related impacts and linkages. In this review we consider the characteristic elements of Arctic fjords and the important dynamical processes. We show how the intense seasonality of these regions is reflected in the varying stratification of the fjords. In particular, we show that sea ice has a central role in terms of the fjord salinity which ultimately influences the exchange with oceanic waters. When the fjord is ice free, wind forcing from the intense down-fjord katabatic winds gives rise to rapidly changing cross-fjord gradients, upwelling and strong surface circulations. The stratification and dimensions of Arctic fjords mean that they are often classed as ‘broad’ fjords where rotational effects are important in their circulation. We refer to the link between the physical oceanographic conditions and the related depositional records throughout.