O. gracilis
# O. gracilis

O. gracilis may refer to:

* Obruchevichthys gracilis, an extinct tetrapod species from Latvia during the Late Devonian
* Oceanites gracilis, the Elliot's storm-petrel, a seabird species
* Oedipina gracilis, a salamander species found in Costa Rica and Panama
* Omphalotropis gracilis, a gastropod species endemic to Guam
* Ormosia gracilis, a legume species found only in Malaysia
* Oxidus gracilis, the "greenhouse millipede", a widely introduced millipede associated with agricultural areas worldwide
* Oxyopsis gracilis, the South American green mantis, a praying mantis species
