This study reviewed structural changes and competitiveness in Korea’s mushroom industry based on long-term trends in production, production value, trade, and distribution prices, and examined the medium- to long-term supply and demand outlook and emerging markets for mycelium-based materials and processed mushroom products. The cultivated area decreased from 3,870 ha in 2005 to 1,885 ha in 2024, while production remained relatively stable at 173,602 tons, indicating increased production efficiency per unit area. Oyster mushroom and king oyster mushroom accounted for 63.1% of total production in 2024, demonstrating a high concentration of production in a limited number of mushroom types. In 2025, mushroom imports increased to 98,268 tons, whereas exports declined to 12,780 tons, resulting in a persistent trade deficit. Distribution prices of major mushrooms showed different patterns across wholesale, retail, and eco-friendly markets; however, differences among these price indicators should not be interpreted directly as distribution margins or causal price transmission because the survey units, markets, and transaction conditions differed. The medium- to long-term outlook for shiitake indicates a decline in domestic production and increasing dependence on imports. In response to these structural changes, five strategic directions are proposed: developing cultivars and products differentiated according to domestic and export-market requirements; strengthening stable domestic production and supply systems for superior cultivars and completed substrates; developing medium-scale automation and process simplification technologies; standardizing distribution-price data and strengthening supply-and-demand monitoring; and expanding functional and high-value mushrooms, processed products, and mycelium-based materials. Mycelium-based materials have potential applications in leather alternatives, packaging, and biocomposites, but further technological development is required to improve production efficiency, biomass yield consistency, material standardization, and cost competitiveness. Overall, an integrated strategy linking cultivar development, production technology, distribution, processing, and export is needed to strengthen the long-term competitiveness and sustainability of Korea’s mushroom industry.