69 or sixty-nine is a sex position in which two people align themselves so that each person's mouth is near the other's genitals, allowing each partner to simultaneously perform oral sex on the other. The participants are thus mutually inverted like in the number 69 (69), hence the code name. In this case, the numerals 6 and 9 are treated more as pictographic symbols than as numerical representations, with the bulbous part representing the heads of the performers.

The name is a translation of the original French, soixante-neuf, which is also sometimes borrowed directly into English. The concept is that both partners can experience sexual stimulation and oral sensation simultaneously, but this can also distract those who try to focus solely on their own pleasure from giving oral sex well. The position can also be awkward for partners who are not similar in height.