As of July 2022, The Hawaii Open is now the Waikiki Cup.
| Hawaii Open Tennis Tournament | |
| City: | Honolulu |
| Country: | United States |
| Surface: | Hard – indoors |
| Draw: | 5 men and 5 women |
| Website: | www.waikikicup.com |
| Completed Event: | 2019 Hawaii Open |
| Men's Singles: |  Sam Querrey |
| Women's Singles: | Danielle Collins |
The Hawaii Open is a hardcourt men's and women's professional tennis tournament held annually in Honolulu, Hawaii. The tournament features players from the WTA and ATP Tour. The invitational tournament occurs immediately before the ATP Tour and WTA Tour begin the new season in late December.
The Hawaii Open features three rounds of single-elimination matches played over three days in a best two-out-of-three set format. Third sets are played as a tie-break with the first to 10 points declared the winner.
The Hawaii Open tournament began as a WTA 125 event in 2016. During the first two years, the tournament was held at the Patsy T. Mink Central Oahu Regional Park during Thanksgiving week in late November.
In 2018, the tournament added a men's draw and became a men's and women's invitational tournament over three days, December 21, 22, and 23. It featured six men and six women and moved to the Blaisdell Arena in Honolulu. The tournament also featured a pro–am at Kailua Racquet Club and a Players Party held at the Prince Waikiki.
The 2019 Hawaii Open presented by Ward Village and Hawaii Tourism was held December 26, December 27, and December 28, in Honolulu, at the Stan Sheriff Center. The tournament featured five men and five women and moved to the Stan Sheriff Center in Honolulu. The tournament also featured a pro–am at the Four Seasons Tennis Centre and a Players Party held at Ward Village.
A mixed doubles match was added to replace the women's singles final due to player withdrawal.
Christian Harrison / Danielle Collins def. Sam Querrey / 
Yanina Wickmayer, 6–4, 6–7(6–8), [10–6]| Year | Champion | Runner-up | Score | |
|---|---|---|---|---|
| 2016 | Catherine Bellis | 6–4, 6–2 | ||
| 2017 |  Zhang Shuai | 0–6, 6–2, 6–3 |
| Year | Champions | Runners-up | Score | |
|---|---|---|---|---|
 Eri Hozumi Miyu Kato | Nicole Gibbs Asia Muhammad | 6–7(3–7), 6–3, [10–8] | ||
| Hsieh Shu-ying Hsieh Su-wei | Eri Hozumi Asia Muhammad | 6–1, 7–6(7–3) |
| Year | Champion | Runner-up | Score | |
|---|---|---|---|---|
| 2018 | Kei Nishikori |  Milos Raonic | 7–6, 7–6 | |
| 2019 | Sam Querrey | Brandon Nakashima | 6–4, 6–7(7–9), [13–11] |
| Year | Champion | Runner-up | Score | |
|---|---|---|---|---|
| 2018 | Elise Mertens | Eugenie Bouchard | 2–6, 7–5, [12–10] | |
| 2019 | Danielle Collins | Angelique Kerber | (walkover) |