"Knock Three Times" is a popular song credited to Tony Orlando and Dawn. The actual singers were Tony Orlando, Toni Wine, and Linda November, prior to the creation of "Dawn" with Telma Hopkins and Joyce Vincent Wilson. The song was released as a single in November 1970, paired with Orlando's other hit song, "Candida" (also written by Toni Wine). The single hit number one on the Billboard Hot 100 in January 1971 and eventually sold six million copies, also claiming the number-one spot on the UK Singles Chart. The song registered well at Adult Contemporary stations, reaching #2 on Billboard's "Easy Listening" survey.

The phrase knock three times can refer to:

• A 1917 Novel by Marion St. John Webb, Knock Three Times (novel)
• A 1968 TV serial, Knock Three Times (TV)
• A 1970 song, Knock Three Times
• A 2001 poem by Bob Rosenthal, Knock Three Times (poem)
• Any of various cultural references to secret knocks, tap codes, etc. especially:
  • Part of a ritual observed in Freemasonry, when opening a lodge or inducting a new member, in which doorknocks are exchanged. The apparent purpose is to prevent admission to persons of a lower degree of initiation than the business being conducted.
  • A ritual observed in cartomancy