It's probably not too surprising to anyone that Fiji Airways allow stopovers in Fiji on the way from Australia to Hawaii but there are two additional options available that may interest some.
Fiji Airways offer three weekly services from Nadi to Honolulu:
• Sundays - direct service
• Fridays - via Apia, Samoa
• Tuesdays - via Christmas Island, Kiribati
On many of their fares to Hawaii, Fiji Airways allow two free stopovers in each direction. This means that if you really wanted to check out a bunch of Pacific paradises, maybe for an epic diving/surfing trip if that's your thing, you could visit Hawaii, Fiji, Samoa and Kiribati all on a return ticket to Hawaii!
Itineraries combining stops in all four destinations can be had for as little as $1528!
Just keep in mind that the flights between Kiribati and Fiji only operate once a week so the duration of your stopover there can only be in increments of weeks, not days.