hairstreak (plural hairstreaks)
- Any of many butterflies, of the subfamily Theclinae, that have hairlike projections on the back wings.
- brown hairstreak (Thecla betulae)
- black hairstreak (Satyrium pruni)
- gray hairstreak (Strymon melinus)
- green hairstreak (Callophrys rubi)
- purple hairstreak (Quercusia quercus)
- white-letter hairstreak (Satyrium w-album)