The horned Australian burrowing mayfly genus Jappa Harker (Leptophlebiidae) is revised based on adult and larval material collected throughout Australia. Five named species [J. campbelli Bae & Finlay, J. edmundsi Skedros & Polhemus, J. furcifera (Eaton), J. serrata Skedros & Polhemus and J. strigata (Eaton 1871) (= J. bicornis Ulmer 1916; = J. kutera Harker 1954, syn. n.)] are recognised, and two new species [J. harkerae n. sp. and J. suteri n. sp.] are described. Descriptions, diagnoses, line-drawings and images of key characters, distributional information, taxonomic remarks and keys to adults and larvae are provided. The species Jappa tristis Harker 1954 is transferred to the genus Tillyardophlebia Dean.