Euphyes bayensis

{{Short description|Species of butterfly}}

{{Speciesbox

| image = Euphyes_bayensis_2191054.jpg

| image_caption = Male

| image2 = Euphyes bayensis female.jpg

| image2_caption = Female

|status=G2

|status_system=TNC

|status_ref={{cite web|url=https://explorer.natureserve.org/Taxon/ELEMENT_GLOBAL.2.120612/Euphyes_bayensis|title=Euphyes bayensis|website=NatureServe Network Biodiversity Location Data accessed through NatureServe Explorer|access-date=5 March 2025|date=28 February 2025|location=Arlington, Virginia|author=NatureServe|publisher=NatureServe}}

| genus = Euphyes

| species = bayensis

| authority = Shuey, 1989[http://www.nic.funet.fi/pub/sci/bio/life/insecta/lepidoptera/ditrysia/hesperioidea/hesperiidae/hesperiinae/euphyes/index.html Euphyes], Site of Markku Savela

| synonyms =

}}

Euphyes bayensis, commonly known as the bay skipper, is a butterfly belonging to the Hesperiidae family. It is found in coastal Mississippi within the United States,[http://www.butterfliesandmoths.org/species/Euphyes-bayensis Butterflies and Moths of North America collecting and sharing data about Lepidoptera] Louisiana and Texas, where it lives in sawgrass marshes of the tidal zone.{{cite book|chapter-url=https://xerces.org/sites/default/files/2019-10/euphyes_bayensis.pdf|chapter=Species Profile: Euphyes bayensis|last1=Vaughan|first1=Mace|last2=Shepherd|first2=Matthew|title=Red List of Pollinator Insects of North America|type=CD-ROM Version 1|access-date=5 March 2025|publisher=The Xerces Society for Invertebrate Conservation|location=Portland, Oregon|editor-last1=Shepherd|editor-first1=M.D.|editor-last2=Vaughan|editor-first2=D.M.|editor-last3=Black|editor-first3=S.H.|date=May 2005}}

The wingspan is 37–44 mm. Adults feed on flower nectar. Within its range there are two generations, in late May and in September. The bay skipper may be confused with Euphyes dion.