King Sejong the Great class destroyer

ROKS Sejong the Great (DDG-991) during the 2008 Busan International Fleet Review
Class overview
Builders:	Hyundai Heavy Industries Daewoo Shipbuilding & Marine Engineering
Operators:	Republic of Korea Navy
Preceded by:	Chungmugong Yi Sun-sin class
Cost:	$923 million (per ship)
Building:	3
Planned:	6
Completed:	3
Cancelled:	0
Active:	3
General characteristics
Type:	Destroyer
Displacement:	8,500 tons standard displacement 11,000 tons full load
Length:	165 m (541 ft 4 in)
Beam:	21.4 m (70 ft 3 in)
Draft:	6.25 m (20 ft 6 in)
Propulsion:	4 General Electric LM2500 COGAG; two shafts, 100,000 shp (75 MW)
Speed:	exceeds 30 knots (56 km/h; 35 mph)
Range:	5,500 nautical miles (10,200 km; 6,300 mi)
Complement:	300-400 crew members
Sensors and processing systems:	AN/SPY-1D(V) multi-function radar AN/SPG-62 fire control radar DSQS-21BZ hull mounted sonar MTeQ towed array sonar system Sagem Infrared Search & Track (IRST) system
Electronic warfare & decoys:	LIG Nex1 SLQ-200K Sonata electronic warfare suite
Armament:	1 × 5 inch (127 mm/L62) Mk-45 Mod 4 naval gun 1 × 30 mm Goalkeeper CIWS 1 × RAM Block 1 CIWS 4 × 4 SSM-700K Hae Sung anti-ship missiles 80-cell Mk 41 VLS SM-2 Block IIIB/IV 48-cell K-VLS 32 × Hyunmoo III land attack cruise missiles 16 × K-ASROC Red Shark in (VLS) 2 × 3 K745 LW Blue Shark torpedoes
Aircraft carried:	Hangar for two Super Lynx or SH-60 Seahawk, one more on landing pad

The Sejong the Great-class destroyers (Sejongdaewang-Ham or Hangul: 세종대왕급 구축함, Hanja: 世宗大王級驅逐艦), also known as KD-III, are three guided missile destroyers of the Republic of Korea Navy (ROKN). The second ship was commissioned in August 2010 and the third in August 2012. As at 2013, the ROKN has deployed three ships with an option for three more; in December 2013 the option to acquire the second three was taken up.

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

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.

At 8,500 tons standard displacement and 11,000 tons full load, the KDX-III Sejong the Great destroyers are by far the largest destroyers in the South Korean Navy, and built slightly bulkier and heavier than Arleigh Burke-class destroyers or Atago-class destroyers to accommodate 32 more missiles. KDX-III are currently the largest ships to carry the Aegis combat system.

Sejong the Great-class destroyers' main gun is the 127 mm/L62 Mk. 45 Mod 4 naval gun, an improved version of the same gun used on other warships from several foreign nations. Point-defense armaments include one 30 mm Goalkeeper CIWS and a RIM-116 Rolling Airframe Missile Block 1 21-round launcher, the first Aegis platform to carry RAM. Anti-aircraft armament consists of SM-2 Block IIIA and IIIB in 80-cell VLS. Anti-submarine warfare armaments consists of both K-ASROC Hong Sahng-uh (Red Shark) anti-submarine rockets and 32 K745 LW Cheong Sahng-uh (Blue Shark) torpedoes. Anti-ship capability is provided by 16 SSM-700K Hae Sung (Sea Star) long-range anti-ship missile, each with performance similar to the U.S. Harpoon. Land-attack capability is provided by the recently developed Hyunmoo-3C (Guardian of the Northern Sky) cruise missile, which is similar to the U.S. Tomahawk.