The flag of the municipality of Haugesund in the county of Rogaland, Norway. Its design is shared with the municipal arms, and shows three gulls, a motif very loosely based upon the previous city arms, which were adopted in 1862. This original design depicted three open barrels of herring and an anchor. These were set against a background consisting of a naturalistic landscape scene, which included three gulls flying in the sky. In terms of symbolism, the aforesaid focal objects represented the city's foundation upon herring and shipping. The number of barrels additionally stood for the three main parts of Haugesund: the mainland, as well as the islands of Risøy and Hasseløy.
In the 20th century, the arms of the city would however become subject to debate, when it came to attention that they were not actually heraldically correct. They would thus not be approvable by the Norwegian government. This led to some differing opinions about how the situation ought to have been resolved, including just keeping the arms without central approval. Those on the other side of the debate had instead effectuated several alternative proposals. Eventually, the city council would decide to take the latter route. Hallvard Trætteberg, who would later become Norway's foremost heraldist, is the author of the proposal that was finally chosen. His design took what was just a background element in the 1862 arms, the gulls, and made them the only charge. The composition's threefoldness was also preserved. As for the symbolism, the gulls are said to gather where there is nourishment to be found, and are explained as representing "the city which gets its livelihood from the sea [...] herring fishing [...] shipping".

By the time that Hallvard Trætteberg could present his proposal on December 7th, 1929, the matter had become rather pressing, as the city now desired officially approved arms to go along with the new city hall, which was nearing completion. The new, simpler design would thanks to its heraldic correctness also be usable as a vexillographically appropriate flag, in the form of a banner of arms. And so, on December 17th, the city council decided upon the new arms and a matching flag. Finally, the following year, the council's decision was approved by royal resolution 1930‐03‐05.
Haugesund kommune, flagg – Arkivverkets digitale fotoarkiv
Hallvard Trætteberg, vectorization by VulpesVulpes42

Older file versions included gulls vectorized by User:Bjarkan, taken from File:Haugesund komm.svg