Lahaina (/ləˈhaɪnə/; Hawaiian: [ləˈhɐjnə]) or Lāhainā is a census-designated place (CDP) in Maui County, Hawaii, United States. On the northwest coast of the island of Maui, it encompasses Lahaina town and the Kāʻanapali and Kapalua beach resorts. At the 2020 census (before the 2023 wildfire), Lahaina had a resident population of 12,702. The CDP spans the coast along Hawaii Route 30 from a tunnel at the south end, through Olowalu, and to the CDPs of Kaanapali and Napili-Honokowai to the north.

A series of wildfires destroyed approximately 80% of Lahaina in 2023, resulting in the deaths of 102 people.

Both Lahaina and Lāhainā are correct orthography in modern Hawaiian.

Protestant missionaries sent by the American Board of Commissioners for Foreign Missions (ABCFM) began organizing a way to write the Hawaiian language with English letters between 1820–1826 after they reached Hawaii.

"The long English sound of i is represented by ai, as in Lahaina, where the second syllable is accented, and pronounced like the English word high".

According to Thrums Hawaiian Annual of 1921 the proper pronunciation of Lahaina is La-hai-ná.

Lahaina has different pronunciations depending on how diacritical marks are applied.

Lahaina is a combination of two Hawaiian words, “lā” which means sun, and “hainā” which means cruel. The varied spellings Lāhainā and Lahaina are commonly interchanged when written in modern English, although the traditional spelling “Lāhainā” is still considered proper.