Goodenia cravenii R.L.Barrett & M.D.Barrett, G. maretensis R.L.Barrett, Goodenia heterotricha M.D.Barrett & R.L.Barrett and Lechenaultia mimica M.D.Barrett & R.L.Barrett are described as new species from the northern Kimberley region of Western Australia. Goodenia cravenii (subg. Goodenia sect. Amphichila DC.) is the smallest species known in the family. Goodenia maretensis (subg. Goodenia sect. Goodenia subsect. Ebracteolatae K.Krause) is known only from the Maret Islands group in the Bonaparte Archipelago. Goodenia heterotricha (subg. Goodenia sect. Goodenia subsect. Ebracteolatae K.Krause) was discovered during a Bush Blitz survey on Home Valley Station in May 2014. Modified keys to these species are presented. Lechenaultia mimica (sect. Latouria (Endl.) Benth.) is known only from the Harding Range and may represent the first instance of floral mimicry to be reported in the genus Lechenaultia. Seed article micromorphology in tropical annual species of Lechenaultia R.Br. is discussed and a key to species is provided. A putative elaiosome, the first report for the genus, was observed on the seed article of L. ovata. All species described here are of conservation priority and are illustrated.