半翅目（学名：Hemiptera）属于昆虫纲，全世界约有133科、超过6万种，由两个亚目所组成：异翅亚目（隐角亚目）和同翅亚目（显角亚目）。异翅亚目包括椿象、水黾、红娘华、水螳螂等；同翅亚目包括蝉、沫蝉、蚜虫等昆虫。目前的半翅目分类仍有争议，同翅目原先被视为独立的目，许多地方也仍将半翅目和同翅目视为不同目。

半翅目的成虫和若虫都有吸管状的口器，牠们大部份是吸取植物汁液，但有些种类会吸取动物或昆虫的体液，甚至于成为其他半翅目的猎食者。

The Hemiptera /hɛˈmɪptərə/ or true bugs are an order of insects comprising around 50,000–80,000 species of groups such as the cicadas, aphids, planthoppers, leafhoppers, and shield bugs. They range in size from 1 mm (0.04 in) to around 15 cm (6 in), and share a common arrangement of sucking mouthparts. The name "true bugs" is sometimes limited to the suborder Heteroptera. Many insects commonly known as "bugs" belong to other orders; for example, the lovebug is a fly, while the May bug is a beetle.