ROKS Sejong the Great (DDG-991) is the lead ship of her class of guided missile destroyer built for the Republic of Korea Navy.

She was the first Aegis-built destroyer of the service and was named after the fourth king of the Joseon dynasty of Korea, Sejong the Great.

[1] The ship features the Aegis Combat System (Baseline 7 Phase 1) combined with AN/SPY-1D multi-function radar antennae.

[1] The Sejong the Great class is the third phase of the South Korean navy's Korean Destroyer eXperimental (KDX) program, a substantial shipbuilding program, which is geared toward enhancing ROKN's ability to successfully defend the maritime areas around South Korea from various modes of threats as well as becoming a blue-water navy.

Republic of Korea Navy (ROKN) has actively participated in the recent iterations of the RIMPAC, which is a unique training opportunity that helps participants foster and sustain cooperative relationships.