A Landing Ship Medium (LSM) was an amphibious assault ship of the United States Navy in World War II. Of a size between that of Landing Ships Tank and Landing Craft Infantry, 558 LSMs were built for the USN between 1944 and 1945. Most of vessels built on this frame were regular transports, while several dozen were converted during construction to specialized roles. Most LSMs were scrapped during the Cold War, but several were sold by the United States Department of Defense to foreign nations or private shipping companies.

This article may require cleanup to meet Wikipedia's quality standards. The specific problem is: information should be included in the "short summary" section of the table describing their overall history. (January 2022)

OPNAV N95 established a new LSM program in 2020. The new LSM will be 350 to 400 ft long, able to operate at 22 knots and have a range of 6500 miles. The cost will be much lower than traditional amphibious shipping, according to a story in the March 2023 Marine Corps Gazette. The piece suggests that a MLR (Marine Littoral Regiment) would need 9 LSMs. As a comparison the Jason class of the Greek Navy is about 380 ft long, with a top speed of 18 knots

• USS LSM(R)-188
• USS LSM(R)-189
• USS LSM(R)-190
• USS LSM(R)-191
• USS LSM(R)-192
• USS LSM(R)-193
• USS LSM(R)-194
• USS LSM(R)-195
• USS LSM(R)-196
• USS LSM(R)-197
• USS LSM(R)-198
• USS LSM(R)-199

• USS Big Black River (LSM(R)-401), later reclassified (LFR-401)
• USS Big Horn River (LSM(R)-402)
• USS Blackstone River (LSM(R)-403)
• USS Black Warrior River (LSM(R)-404), later reclassified (LFR-404)
• USS Broadkill River (LSM(R)-405), later reclassified (LFR-405)
• USS Canadian River (LSM(R)-406)
• USS Chariton River (LSM(R)-407)
• USS Charles River (LSM(R)-408)
• USS Clarion River (LSM(R)-409), later reclassified (LFR-409)
• USS Clark Fork River (LSM(R)-410)
• USS Cumberland River (LSM(R)-411)
• USS Desplaines River (LSM(R)-412), later reclassified (LFR-412)

• USS Elk River (LSM(R)-501), later reclassified (IX-501)
• USS Escalanteo River (LSM(R)-502)
• USS Flambeau River (LSM(R)-503)
• USS Gila River (LSM(R)-504)
• USS Grand River (LSM(R)-505)
• USS Green River (LSM(R)-506)
• USS Greenbrier River (LSM(R)-507)
• USS Gunnison River (LSM(R)-508), later reclassified and renamed USS Targeteer (YV-3)
• USS Holston River (LSM(R)-509)
• USS James River (LSM(R)-510)
• USS John Day River (LSM(R)-511)
• USS Lamiolle River (LSM(R)-512), later reclassified (LFR-512)
• USS Laramie River (LSM(R)-513), later reclassified (LFR-513)
• USS Maurice River (LSM(R)-514)
• USS Owyhee River (LSM(R)-515), later reclassified (LFR-515)
• USS Pearl River (LSM(R)-516)
• USS Pee Dee River (LSM(R)-517)
• USS Pit River (LSM(R)-518)
• USS Powder River (LSM(R)-519)
• USS Raccoon River (LSM(R)-520)
• USS Rainy River (LSM(R)-521)
• USS Red River (LSM(R)-522), later reclassified (LFR-522)
• USS Republican River (LSM(R)-523)
• USS Saint Croix River (LSM(R)-524)
• USS St. Francis River (LSM(R)-525), later reclassified (LFR-525)
• USS St. Johns River (LSM(R)-526)
• USS St. Joseph's River (LSM(R)-527)
• USS St. Mary's River (LSM(R)-528)
• USS St. Regis River (LSM(R)-529)
• USS Salmon Falls River (LSM(R)-530)
• USS Smoky Hill River (LSM(R)-531), later reclassified (LFR-531)
• USS Smyrna River (LSM(R)-532)
• USS Snake River (LSM(R)-533)
• USS Thames River (LSM(R)-534)
• USS Trinity River (LSM(R)-535)
• USS White River (LSM(R)-536), later reclassified (LFR-536)

• USS Gypsy (ARS(D)-1), authorized as LSM-549
• USS Mender (ARS(D)-2), authorized as LSM-550
• USS Salvager (ARS(D)-3), authorized as LSM-551, later reclassified to YMLC-3
• USS Windlass (ARS(D)-4), authorized as LSM-552, later reclassified to YMLC-4

Dates are launch dates.^[2]

• Brown Shipbuilding: Houston, TX: 254 (May 1944 - Apr 1946)
  • purpose-built yard for the war effort
• Charleston Navy Yard, North Charleston, SC: 121 (May 1944 - Nov 1945)
  • traditional military yard
• Dravo Corporation, Wilmington, DE: 65 (Apr 1944 - May 1945)
  • purpose-built yard for the war effort
• Pullman Company, Chicago, IL: 44 (May 1944 - May 1945)
  • traditional rail car manufacturer
• Federal Shipbuilding and Drydock Company, Newark, NJ: 42 (May 1944 - Feb 1945)
  • traditional civil and military yard
• Western Pipe and Steel, San Pedro, CA: 32 (Aug 1944 - Mar 1945)
  • traditional civil yard

Delivery:^[2]

• Q2 1944: 74
• Q3 1944: 129
• Q4 1944: 132
• Q1 1945: 111
• Q2 1945: 58
• Q3 1945: 30
• Q4 1945: 15
• 1946: 9

One LSM, USS LSM-45, survived in its original configuration until around 2010. It was in storage at Marine Station Camp Lejeune in Jacksonville, North Carolina. It was slated to become the centerpiece of the Museum of the Marine, but due to changed plans, was scrapped between 2010 and 2014.^{[citation needed]}

As of February 2023 the US Marine Corps has proposed the purchase of 18 to 35 modern LSMs; this LSM concept was previously known as the Light Amphibious Warship (LAW).^[3][4]

• List of United States Navy Landing Ship Mediums
• Landing Ship, Infantry
• Mark 8 Landing Craft Tank
• Landing Ship Medium#Light Amphibious Warship (LAW)