This study discusses various issues and possible solutions related to groundwater resource and water quality in Korea. Groundwater is an important water resource in Korea, accounting for approximately 13% of the total annual domestic, agricultural, and industrial water supplies. From 1996 to 2014, groundwater usage increased by 45% while the number of wells increased by 102%. However, repeated occurrences of Foot and Mouth Disease and Avian Influenza led to nationwide mass burials of livestock and major effect of groundwater contamination. In coastal areas, anthropogenic activities were considered as the cause of seawater intrusion near the shore and far (7,000 m) from the coast. Thousands of abandoned metal mines and unregulated mining wastes have serious environmental effects in Korea; crop cultivation in metal contaminated soil and irrigation using metal contaminated water negatively affect human health. Moreover, urbanization is a major source of groundwater contamination due to intensified industrial activities. The Korean government has made major efforts to deal with the groundwater issues, including implementation of the Groundwater Act in 1996. Since then, various national monitoring systems have been established to examine changes in groundwater quality and quantity. Additional recent important groundwater quality issues need attention and must be resolved to ensure groundwater safety in Korea.