Diane Suzuki was a nineteen-year old dancer and student at the University of Hawaii at Manoa who disappeared on July 6, 1985, and has since been the focus of one of the most notorious modern criminal investigations in the history of the state of Hawaii. Led by Detective Lieutenant William Kato, the Diane Suzuki investigation was the instance in which luminol and other technological advances in forensic science were first used by the Honolulu Police Department.

Suzuki was a female resident of Halawa, 5 feet 1 inch tall, 109 pounds, with a slim build, and of Japanese descent. Suzuki was last seen at about 5 p.m. on July 6, 1985, outside the Woodson Institute of Dance in Aiea, where she was employed as a dance instructor.

During the same time period in Hawaii, there were the unsolved killings of at least nine women on Oahu. The deaths of Lisa Au, Regina Sakamoto, and others all over the island, led many to believe that there was a crime wave.

Although no charges have ever been filed in the case, it is widely believed that the murder suspect was a fellow dance instructor who murdered Suzuki in the bathroom of the Woodson Institute in Aiea. The discovery of blood evidence at the site led to legislation that changed Hawaii's harassment laws to include stalking, and changed the status of TRO violations to a class C felony (with a maximum penalty of 5 years in jail) in the hope of preventing further violence against women.

In 1993, Keith Kaneshiro, who was then prosecuting attorney for the City and County of Honolulu, attempted to re-open the case, but after more than 300 hours of grand jury testimony and thousands of dollars spent on the investigation, no charges were filed. The case remains unsolved as of 2004.