Rhizanthella speciosa is a species of flowering plant in the orchid family and is endemic to Barrington Tops in New South Wales.

Rhizanthella speciosa is a leafless, sympodial herb with a horizontal rhizome and underground stem probably similar to that of R. slateri.

After pollination, the flower produces a fleshy, narrow cylindrical drupe that is pinkish to light maroon when ripe.

[2][3] This species of underground orchid was discovered in 2016 by scientific illustrator Maree Elliot and formally described in 2020 by Mark Clements and David Jones in the journal Lankesteriana from material collected in Barrington Tops National Park.

[3][4][5] Rhizanthella speciosa was found under dense leaf litter in tall wet sclerophyll forest of the Barrington Tops National Park with Sydney blue gum, tallowood, and turpentine, and a well-developed rainforest subcanopy with Trochocarpa laurina and Synoum glandulosum.