Pamela Wang from Kealakekua on Big Island was out walking when she saw the 5.2lb (2.35kg) fruit. "It was as big as my head," she told the West Hawaii Today newspaper.
Ms Wang has submitted an application to Guinness World Records. In 2009 a 4.8lb avocado was verified in Venezuela.
"Smashed avocado" on toast has become a popular breakfast among young people in the West.
It has come to symbolise a generational wealth divides after an Australian columnist lambasted young people worried about high property prices for spending money on the dish instead of saving.