Populations of Owenia from various localities around Australia were examined in detail and a large number of measurements were made on several individuals from each location. Using the means of these measurements a variety of statistical analyses were carried out which identified three major groups of Owenia and the various characters that delineate these groups. Each of these groups is described as a new species and the diagnostic features of all the described species of Owenia are provided. A cladistic analysis was undertaken to investigate the relationships of these species to other described species from the region. This study shows the usefulness of morphometrics in distinguishing species in this morphological conservative genus and provides further support that the so called ‘cosmopolitan species’O. fusiformis delle Chiaje 1841 does not occur in Australian waters.