Map - Waipahu, Hawaii (Waipahu)

Waipahu is a former sugarcane plantation town and now census-designated place (CDP) located in the Ewa District on the island of Oahu in the City & County of Honolulu, Hawaii, United States. As of the 2020 census, the CDP population was 43,485. The U.S. postal code for Waipahu is 96797.

Waipahu is the name of an artesian spring. In Hawaiian, Waipahu is derived from wai, meaning water, and pahū, meaning "burst or explode"; combined, Waipahu means "water forced up (as out of a spring)". The early Native Hawaiians took pleasure in the cool and clear water gushing from the ground and named this spring Waipahu. Before the Western civilization set foot in Hawaii, the Hawaiians considered Waipahu to be the capital of Oahu. Royalty in the Kingdom of Hawaii would often gather and enjoy the fresh water from the spring Waipahu.

In 1897, Oahu Sugar Company was incorporated, and its board of directors located the sugar mill in Waipahu. It had 943 field workers. There were 44 Hawaiians, including 10 minors; 57 Portuguese; 443 Japanese, 408 of them contract laborers; and 399 Chinese, 374 of whom were contract laborers. The company's managers from 1897 to 1940 were August Ahrens (1897–1904), E.K. Bull (1904–1919), J.B. Thomson (1919–1923), E.W. Greene (1923–1937), and Hans L'Orange (1937–1956).

In the early days of the plantation, each worker was assigned a number inscribed on a metal disc about the size of a silver dollar. The numbers 1 through 899 identified Japanese alien; 900 through 1400 were Japanese who were American citizens or Hawaii-born. The 2000 and 2100 series were Portuguese laborers, 2200 Spanish, 2300 Hawaiian, 2400 Puerto Rican, 3000 Chinese or Korean, 4000 and 5000 Filipino. The company imported laborers from many different countries including the Philippines, Japan, China, Portugal, and Norway. Very few laborers working for the Oahu Sugar Co. were Hawaiian. The majority of the company's first laborers were either Japanese or Chinese. Each ethnic group was broken up into different camps. This division was said to have been the result of different cultures and language barriers.

Plantation workers lived by what was called The Plantation System. Field workers received an average monthly salary of $12.50. However, Filipino immigrants were paid less than all of the other laborers because they were the cheapest to import. The Filipinos, on average, made less than $10.00 a month. The Chinese generally were paid the most with a monthly average of $15.00.

In 1932 the Oahu Sugar Co. opened a continuation school, and allowed a half-day off from work once a week for workers to attend. Those who weren't available during the day could also attend evening courses. This was to give them a chance to better their knowledge for a better job.

During the surprise attack on Pearl Harbor on December 7, 1941, Imperial Japanese Navy (IJN) planes fired at the sugar mill in Waipahu, killing a civilian and injuring seven others.

Amfac acquired the company in 1961. Oahu Sugar Company shut down plantation operations after the 1995 harvest.

In 1923, the Oahu Sugar Company field also served as the community center which featured band concerts, sporting events, and carnivals. Later, the athletic field was renamed Hans L'Orange Field. Today, the park is primarily used for baseball, and is the home field of Hawaii Pacific University's men's baseball team, the Sea Warriors. It was the home field of the Hawaii Winter Baseball teams the North Shore Honu and West Oahu CaneFires until 2008.

In 1973, the City and County of Honolulu and the State of Hawai'i purchased 40 acre opposite the Waipahu sugar mill to establish the Waipahu Cultural and Garden Park. The park is known today as the Hawai'i Plantation Village. Hawai'i Plantation Village is a living history museum located in Waipahu.