Seaweed aquaculture production in Korea is dominated (> 99% of total production) by relatively few species: the brown kelps, Saccharina japonica and Undaria pinnatifida; and the red seaweed Pyropia ('gim' in Korean). The cultivation of Pyropia started as early as in 1623. Seaweed aquaculture industry, however, started to grow rapidly since 1960s, when P. tenera and P. yezoensis strain selections were actively occurred. Intra-species selective breeding of Pyropia started in 1980s and inter-species selective breeding in 1990s. For Undaria, strain selections started in 1970s and selective breeding since 1980s. For Saccharina, strain selections started in 1960s and selective breeding from 1970s. For Pyropia and Saccharina, mutant and genetic studies have also conducted recently. Seaweed aquaculture industry have grown dramatically in Korea, but there are still many challenges to overcome, including developing new cultivars considering global climate change, and developing environmentally sustainable cultivation technologies (e.g. integrated multi-trophic aquaculture, offshore cultivation, land-based cultivation, etc.), diversifying species, and new seaweed products and markets. More details about the history, current technologies and future directions of seaweed aquaculture in Korea will be presented.