- Knuckles the Echidna (Archie), from the Archie Comics.
- Knuckles the Echidna (Sonic the Comic), from Sonic the Comic.
- Knuckles the Echidna (Sonic X), from Sonic X.
- Knuckles the Echidna (Sonic Underground), from Sonic Underground.
- Knuckles the Echidna (Sonic the Hedgehog: The Movie), from Sonic the Hedgehog: The Movie.
- Knuckles the Echidna (Sonic Boom), from Sonic Boom.
Alternate Reality Characters
- Knuckles the Echidna (Dark Mobius), from the alternate reality of Dark Mobius.
- Knuckles the Echidna (Light Mobius), from the alternate reality of Light Mobius.
- Brass Knuckles
- Knuckles, from the zone which most closely follows the games.
- Knuckles the Echidna (Mirror Dimension), from the Mirror Dimension.
- Knuckles, a miniseries spin-off to Archie Comics' Sonic comic series.
- Knuckles: The Dark Legion, a second miniseries spin-off
- Knuckles the Echidna, an ongoing comic series, following on from Knuckles: The Dark Legion.
- The Knuckles Knock-Out Special, a one-shot special spin-off of Sonic the Comic, featuring Knuckles and the Chaotix
- Knuckles the Echidna in Sonic the Hedgehog 2, an alternate version of Sonic the Hedgehog 2 featuring Knuckles as the main playable character.
- Knuckles' Chaotix, a SEGA 32X game featuring Knuckles.
- Knuckles Soccer, an LCD game released by McDonald's.
- Knuckles Baseball
- Knuckles' Treasure Hunt
- Knuckles (item), an item that appears in Tails Adventure.
- The Knuckles Tribe, a group of Echidnas that had existed since ancient times. Knuckles is a descendant of said tribe.