It is a common species with a single narrow leaf and up to fifteen distinctly cup-shaped, prominently striped blue or mauve flowers with crowded, finger-like glands on top of the anther.

The column is dark blue and divided into three parts with black and yellow tips.

[2][3][4] Thelymitra campanulata was first formally described in 1840 by John Lindley and the description was published in A Sketch of the Vegetation of the Swan River Colony.

[5] The specific epithet (campanulata) is derived from the Latin word campanula meaning "bell".

[2][3][8] Thelymitra campanulata is classified as "not threatened" by the Western Australian Government Department of Parks and Wildlife.