Knuckle (disambiguation)
A knuckle is a joint on the hand.
Knuckle or knuckles may also refer to:

Arts, entertainment, and media
Knuckle (film) a 2011 documentary about bare knuckle boxing in Ireland
Knuckle Bine, a character from the anime/manga series Hunter × Hunter
Knuckles the Echidna, a fictional character from the Sonic the Hedgehog video game series
Knuckles the Echidna (comics), American comic book series
Knuckles (TV series), an upcoming television miniseries

Biology and anatomy
Knuckles, the dorsal crenulations (bumps) of the gray whale where most whales have a dorsal fin
Knuckle-walking,  a form of quadrupedal walking in which the forelimbs hold the fingers in a partially flexed posture that allows body weight to press down on the ground through the knuckle
Pork knuckle, a part of a pig's leg used as the basis of the traditional German dish Eisbein

People with the name
Knuckles Boyle (1909-1943), American football player
Frankie Knuckles (1955–2014), American  DJ, record producer, and remixer

Other
Brass knuckles (also called knuckles), weapons used in hand-to-hand combat
Knuckle coupler, a railway coupling, a mechanism for connecting rolling stock in a train
Knuckle joint (mechanical), used to connect the two rods which are under the tensile load
Knuckles Mountain Range, Sri Lanka

See also
Knuckle Sandwich (disambiguation)
Knuckleball, or knuckler, a baseball pitch