Gardenia is an Old World genus of about 200 species. A bibliographic survey on Sulawesi Gardenia, a region extremely rich in plant diversity, but poorly explored botanically, enumerated five species, namely G. affinis, G. forsteniana, G. mutabilis, G. pelenkahuana, and G. vernicosa. Of these, G. mutabilis remains in Gardenia based on current generic delimitation using various morphological characters of the vegetative and floral parts. Three taxa, G. affinis, G. forsteniana, and G. pelenkahuana, have been reassigned to genera such as Porterandia or Rothmannia. Meanwhile, G. vernicosa was found to have been erroneously listed for Sulawesi. As herbarium materials labeled as G. mutabilis were examined and sorted, they were found to be heterogeneous and included two novelties, G. kabaenensis and G. longistipula, described and illustrated here. These two new taxa are distinguished from G. mutabilis based on calyx form and tube length, and stipule length.