The simple version of Thelymitra batesii.

Thelymitra batesii, commonly called the plump sun orchid, is a species of orchid that is endemic to South Australia.

Thelymitra batesii, commonly called the plump sun orchid, is a species of orchid that is endemic to South Australia. It has a single fleshy, channelled, dark green leaf and up to eight mauve to bluish purple flowers that are pinkish with darker stripes on the back. The unopened flower buds are distinctly plump.