WW

WW may refer to:

• Bmibaby (IATA airline code)
• WOW air (IATA airline code)
• Winchester and Western Railroad reporting mark
• William H. Webster, a director of the FBI and CIA, referred to in the Kryptos sculpture as "WW"
• William Whopper, an evil property developer in the Australian 1980 children's TV programme Secret Valley
• an abbreviation for whitewater in the International Scale of River Difficulty
• "Wrong word" in proofreading
• the car number plate code for Wicklow, Ireland
• the car number plate code for Westerwaldkreis, Germany

In entertainment:

• WW (album), a 2005 album by the Norwegian metal group Gehenna