WTOS may refer to:

• WTOS (AM), a radio station (910 AM) licensed to Bangor, Maine, United States
• WTOS-FM, a radio station (105.1 FM) licensed to Skowhegan, Maine, United States

• Calliophis haematoetron
• Calliophis intestinalis
• Calliophis maculiceps
• Calliopius of Antioch
• Callioplana marginata
• Calliopsis atkinsoniana
• Calliopsis basalis
• Calliopsis bicolor
• Calliopsis cardaminefolia
• Calliopsis diversifolia
• Calliopsis drummondii
• Calliopsis nudata
• Calliopsis palmata
• Calliopsis (plant)
• Calliopsis rosea
• Calliopsis tinctoria
• Calliopum
• Calliostoma adspersum
• Calliostoma aequisculptum
• Calliostoma alternum
• Calliostoma anderssoni
• Calliostoma angolensis
• Calliostoma antonii
• Calliostoma apicinum
• Calliostoma argentum