In this chapter, we review the salient features of the coastal wetlands in the continent of Australia and the islands of New Zealand (Figure 11.1), both of which are in the Ramsar Oceania biogeographic region (Figure 6.1). Australia is the smallest of the world’s continents, but it covers a large latitudinal range, stretching from 11° S of the Equator to the edge of the cool temperate climate region at ~44° S; its coastline includes many estuarine areas (Figure 11.1), although it has no large deltas in serious danger of destruction by rising sea level. New Zealand is a much smaller country, extending from ~35 to 48° S; it is one of the last of the Pacific regions to be colonized by humans, but already has lost 90% of its wetlands (Mitsch and Gosselink, 2007; Silliman et al., 2009). Southern Australia and New Zealand North Island have the southernmost of the world’s mangroves, but these countries differ greatly in climate and tectonic setting. Australia has the world’s oldest rocks, which largely have been tectonically stable for >65 million years, whereas New Zealand is part of the Polynesian active ‘Ring of Fire’. The two Australasian subregions are therefore discussed separately in this book.