Rotary may refer to:

• Rotary motion
• Rotary dial, a rotating telephone dial
• Rotary engine (disambiguation), multiple types of engines called "rotary"
• Rotary latch
• Rotary milking shed, a type of milking shed used in the dairy industry
• Rotary snowplow, one type of railroad snowplow used especially for deep snow removal
• Rotary system, a type of pre-electronic telephone switch
• Rotary table (drilling rig), a device used to apply directional force to a drill string
• Rotary tiller, a motorised cultivator
• Rotary woofer, a type of loudspeaker capable of producing very low frequency sound
• Rotary wing aircraft

• Rotary International, or Rotary Club, an international service organization founded in the United States
  • Rotary Foundation, non-profit foundation of Rotary International
  • Rotary Scholarships, scholarships offered by the organization
• Rotary Watches, a Swiss watchmaker

• Rotary (intersection) or roundabout, a circular roadway intersection
• "The Rotary", a song by Andy Partridge from Take Away / The Lure of Salvage