Utricularia simplex is a terrestrial bladderwort endemic to the south coast of Western Australia. Its name refers to its simple 1-flowered scapes.

The species has small blooms that are coloured lilac. The lower corolla lip is domed in shape, with edges that flare upwards at their widest point. The palate is coloured yellow. The upper corolla lip is relatively large and adopts an upwards posture. The spur is thrust forwards horizontally into the lower corolla lip.

U. simplex is restricted to the wetlands of Western Australia’s south coast. I found the species near Walpole, where it was growing in a draining ditch dug aside a road that bisected a swamp. The species was growing aside Drosera hamiltonii.

The species is closely related to U. lateriflora, which shares a very similar floral morphology. In the wild, the two species never overlap in range, with U. lateriflora being present only in the eastern states.