ROKS Cheonan (FFG-826) is the seventh ship of the Daegu-class frigate in the Republic of Korea Navy. She is named after the city, Cheonan.

The Daegu class is an improved variant of the Incheon-class frigate. Modifications to the Incheon class include a TB-250K towed array sonar system and a 16-cell Korean Vertical Launching System (K-VLS) that is able to deploy the K-SAAM, Hong Sang Eo anti-submarine missile, and Haeryong tactical land attack cruise missiles.^[1]

The hull design is generally based on the one of the Incheon class. However, as a part of weapon system modifications, the superstructure has been significantly changed. The hangar and a helicopter deck over the stern has been enlarged to support the operation of a 10-ton helicopter.^[2][3]

Cheonan was built by Hyundai Heavy Industries at its Ulsan shipyard and launched on 9 November 2021.^[4] Cheonan was commissioned on 19 May 2023.^[4]

On 22 January 2024, Commander Park Yeon-soo, who had served as the operations officer on ROKS Cheonan (PCC-772) when it was sunk by a North Korean torpedo on 26 March 2010, took command of the new Cheonan.^[5]