Tanypus complanatus sp. n., Pseudosmittia remigula sp. n, and Polypedilum (Tripodura) silhoettarium sp. n. are described as male imagines and Clunio gerlachi sp. n. as male and female imago. The male imagines of Larsia pallidissima (Kieffer), Gymnometriocnemus (Gymnometriocnemus) mahensis (Kieffer), Pseudosmittia xanthostola (Kieffer) and Polypedilum (Polypedilum) glabripenne (Kieffer) are described for the first time. The male imagines of Paramerina minima (Kieffer), Smittia megalochirus (Kieffer) n. comb., Smittia mahensis (Kieffer) and Pseudosmittia melanostola (Kieffer); and the female imago of Pseudosmittia xanthostola (Kieffer) are redescribed. A key to the known chironomids of the Seychelles is given. Twenty-eight chironomid species are known from the Seychelles, 23 from the island of Mahé, 12 from Silhouette, 3 from Curieuse, 2 from Anonyme and 1 from each of Fregate, North and the coralline Alphonse. The likely marine intertidal species appears to have their closest relatives in Micronesia and the Pacific, while the freshwater chironomid fauna appear to have more Afrotropical relatives.