1. Global aquaculture production continues to increase, whilst capture fisheries stagnate. Many wild fisheries have been overexploited. Cultivation, if managed sustainably, is a viable alternative. 2. The seaweed industry is undergoing a rapid global expansion and currently accounts for ~49% of the total mariculture production. Unabated exponential growth in the last 50 years has meant that the value of the industry reached US$6.4 billion in 2014, providing jobs, predominantly in developing and emerging economies. 3. There is increasing need to address new challenges imposed by trade and market demand. Case studies clearly show that valuable lessons can be drawn from the major seaweed-producing nations and other aqua- and agriculture sectors. 4. Improving biosecurity, disease prevention and detection measures are critical, together with establishing policies and institutions. This will provide incentives and steer the long-term economic and environmental development of a sustainable seaweed aquaculture industry. 5. This policy brief highlights key issues that need to be addressed to create longterm sustainability of this emerging global industry, as it prepares itself for playing an important role in the ‘blue’ ocean economy agenda