The flag of Hopper Island consists of thirteen equal horizontal stripes of red (top and bottom) alternating with white, and a blue circle bearing a golden seabird as an emblem. The thirteen stripes were inspired by the American flag design. The blue circle symbolizes various things, including Hopper Island's total isolation as a spot in the ocean, but also the unlimited freedom the inhabitants envisioned for themselves. In a more concrete sense, the circle stands for the island itself, which consists of an approximately round lagoon surrounded by a strip of land on all sides. The golden seabird is seen as a symbol for the Pacific Ocean, but it also stands for freedom.

The flag was first hoisted for the first time on January 1, 1948 in what is now called Coronado. The flag was designed and stitched by Rose Gilpatrick. The original flag was flown until somewhere in 1950. Gilpatrick made two or three more flags of the same design, until the Assembly decided to order the flags made by an Australian company. Nowadays, Hopper Island flags are printed by a specialized company in the United Kingdom.