Эскадренные миноносцы УРО типа «Король Седжон» (KDX-3)

The Sejong the Great-class destroyers, also known as KDX-3, are three guided missile destroyers of the Republic of Korea Navy (ROKN).

On 20 April 2007, South Korean Chief of Naval Operations announced that the lead ship of KDX-3 class destroyers will be referred to as Sejong the Great. Sejong the Great is the fourth king of the Joseon Dynasty of Korea. He is credited with the creation of the indigenous Korean system of writing.

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-3 Sejong the Great destroyers are the largest destroyers in the South Korean Navy and larger than most destroyers in the navies of other countries. They are built slightly bulkier and heavier than Arleigh Burke-class destroyers or Atago-class destroyers to accommodate 32 more missiles. As such, some analysts believe that this class of ships is more appropriately termed a class of cruisers rather than destroyers. KDX-3 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 other 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 3A and 3B in 80 total Mk 41 VLS cells. Block 3B has added infrared (IR) induction mode to Block 3A, improving interception capability.

Anti-submarine warfare armaments consists of both K-ASROC Hong Sang-uh (Red Shark) anti-submarine rockets, which have the same form as the U.S. ASROC, and 32 K745 LW Cheong Sang-uh (Blue Shark) torpedoes. Anti-ship capability is provided by 16 SSM-700K Hae Sung (Sea Star) long-range anti-ship missiles, each with performance similar to the U.S. Harpoon. Land-attack capability is provided by the Hyunmoo 3 cruise missile.

The ship features the Aegis Combat System (Baseline 7 Phase 1) combined with AN/SPY-1D(V) multi-function radar antennae. This gives the destroyers the ability to track missiles launched from anywhere in North Korea.

The Sejong the Great-class destroyers are often compared to the Arleigh Burke and Atago classes because they utilize the AN/SPY-1D multi-function radar, and have similar propulsion and capabilities. One notable difference between the Sejong the Great-class ships and Arleigh Burkes is the number of VLS cells. Destroyers of the Sejong the Great class have a capacity of 128 missiles, as opposed to 96 on the Arleigh Burke class and the Japanese Atago-class destroyers. The Sejong the Great class is thus one of the most heavily armed ships in the world, with greater missile capacity than the Chinese People's Liberation Army Navy Type 055 destroyer (112 VLS cells) and the U.S. Navy Ticonderoga-class guided missile cruiser (122 VLS cells).

Another similarity to Arleigh Burke Flight 2A and Atago-class destroyers is the presence of full facilities for two helicopters, a feature missing from earlier Arleigh Burke and Kongō-class destroyers.

The Sejong the Great class is KDX-3 Batch 1, and Korean Navy is planning 3 ships of KDX-3 Batch 2. Under the deal, HHI will deliver the first ship by November 2024.