The Battle of Korea Strait was a single ship action fought on the first day of the Korean War on 25–26 June 1950, between the navies of South Korea and North Korea. A North Korean troop transport carrying hundreds of soldiers attempted to land its invasion force near Busan but was encountered by the South Korean patrol ship ROKS Baekdusan and sunk. It was one of the first surface actions of the war and resulted in an important South Korean victory.

The Battle of Chuncheon was one of a series of coordinated attacks beginning on 25 June 1950 that marked the beginning of the Korean War.

The Battle of Ongjin Peninsula was a series of battles that occurred in Ongjin Peninsula between 25 and 26 June 1950 and was a part of the Operation Pokpung and Operation Western Region that marked the beginning of the Korean War. On 25 June, the Korean People's Army (KPA) 3rd 38-Guard Brigade, reinforced with the 1st Infantry Regiment of the 6th Infantry Division, launched a surprise attack on the Republic of Korea Army (ROKA) 17th Infantry Regiment in Ongjin Peninsula, modern-day Ongjin and Kangryong. The battle ended on 26 June with a KPA victory, but many ROKA troops were able to escape from the peninsula.