In this paper, the first of a series providing a systematic revision of all Rotifera now known from Australian inland waters, the common bdelloid rotifers are reviewed. The group is epiphytic or epibenthic in habit, but some species commonly occur in open water of billabongs, lakes and rivers, particularly in association with algal blooms. Frequent occurrence of bdelloids in plankton collections necessitates diagnostic keys to their identification. For the common species only, morphological features of taxonomic significance are described and figured to facilitate further study.