Coastlines in Atlantic Canada are influenced by microtidal, mesotidal, macrotidal, and hypertidal regimes. Although the hypertidal inner Bay of Fundy has attracted the most attention from geomorphologists and visitors, all atlantic tidal environments are marked by interesting and distinctive coastscapes, influenced by pre-existing topography, coastal bedrock lithology and Quaternary sediment, sea ice activity, and subtidal, intertidal, and supratidal vegetation. The hypertidal-macrotidal Bay of Fundy of New Brunswick and Nova Scotia is marked by extensive tidal flats and channels. Saltmarshes and barrier islands characterize the mesotidal Gulf of St. Lawrence coastlines of New Brunswick and Prince Edward Island. Tides and sea ice influence mesotidal-upper microtidal coastlines of Newfoundland and Labrador. In addition to their geomorphic significance, atlantic Canadian tidal coastlines also are valuable resources from multiple ecological and socio-economic viewpoints. Subtidal and intertidal areas support a variety of organisms and ecological communities. Saltmarshes are marked by sequences of communities conditioned by salinity and terrestrial input. Tide-dominated coastlines have been occupied by humans since shortly after deglaciation, and tidal activity has significant impacts on human coastal utilization. Interest in exploiting tidal energy remains high, but must be balanced against potential ecological impacts. Coastal tourism is a significant economic driver in Atlantic Canada, with tidal coastlines representing major attractions.