Ailinglaplap or Ailinglapalap (Marshallese: Aelōn̄ļapļap, [ɑ̯ɑ͡æe̯elʲe͡ɤŋ(ʌ)ɫɑ͡æbʲ(æ͡ɑ)ɫɑ͡æpʲ]) is a coral atoll of 56 islands in the Pacific Ocean, and forms a legislative district of the Ralik Chain in the Marshall Islands. It is located 152 kilometres (94 mi) northwest of Jaluit Atoll. Its total land area is only 14.7 square kilometres (5.7 sq mi), but it encloses a lagoon of 750 square kilometres (290 sq mi). The economy of the atoll is dominated by coconut plantations. The population of the atoll was 1,959 in 1999. Jabat Island is located off the coast of Ailinglaplap Atoll. The former president of the Marshall Islands, Kessai Note, was born on Jeh Island, Ailinglaplap Atoll.
"Ailinglaplap" translates as "greatest atoll" (aelōn̄ (atoll) + ļapļap (superlative suffix)), because the greatest legends of the Marshallese people were created there. The four major population centers on Ailinglaplap Atoll are the settlements of Woja, at the westernmost end of the atoll, Jeh in the northeast, and Airok and Bouj in the south.
In 1884, the Empire of Germany claimed Ailinglaplap Atoll along with the rest of the Marshall Islands. A number of European trading stations were established on the islands to Ailingkaplap as part of the copra trade. After World War I, the island came under the South Pacific Mandate of the Empire of Japan. Following the end of World War II, it came under the control of the United States as part of the Trust Territory of the Pacific Islands until the independence of the Marshall Islands in 1986.