Punahou's annual two-day fundraiser draws thousands of Carnival-goers. The proceeds from Carnival help support the more than 400 students at Punahou who benefit from its financial aid program.

From rides and games to crafts and food, hosting Carnival takes months of preparation prior to opening day on the first Friday in February. Every year, the junior class organizes, plans and executes the theme and activities for the event. Their parents and other volunteers from across the Punahou community also contribute their time to prepare for and staff the many Carnival booths and activities.

The tradition began in 1932, when, during the Depression, Academy students hosted an "Oahuan Campus Carnival" to raise money for the yearbook. Held on Rice Field, it took place early one Friday afternoon in April and lasted until late evening, with the usual Carnival fare and games. In the end, they raised $240 for the Oahuan. In 1936, the PTA and the junior class banded together and introduced the first Carnival rides.

Today, the Carnival features around 60 different booths with food, games, rides and other Carnival-going fun, appealing to all ages. Carnival favorites include the senior class Variety Show, the malasada and mango chutney booths, and the hugely popular white elephant sale.