Utricularia hamiltonii is a terrestrial bladderwort endemic to the Top End of the Northern Territory.
The species has small blooms that are coloured purple. The lower corolla lip is distinctively squarish. The palate has a long yellow streak and is surrounded by dark purple markings. The upper corolla lip has two triangular lobes which resemble dog ears. The spur is tubular and bent forwards.
U. hamiltonii is found in wet areas within grassy floodplains in the Top End, blooming at the end of the wet season as its niche begins to dry.
It is similar to U. triflora and shares similar markings and floral morphology. U. hamiltonii is distinguished by its short scapes with singular blooms (U. triflora has long scapes and produces flowers in sets of three).