Series 1974
- Keitaro Jin, a robotic scientist, is attacked by the terrorist organization G.O.D., who steal his technology and leave him gravely injured. In his dying moments, he manages to convert his son, Keisuke Jin, into Kamen Rider X. With his new powers, Keisuke devotes his life to destroy G.O.D. and defeats their first Kaijin, Neptune. (Ep. 1)
- X-Rider defeats Pannic. (Ep. 2)
- X-Rider defeats Hercules. (Ep. 3)
- X-Rider defeats Medusa. (Ep. 4)
- X-Rider defeats Cyclops. (Ep. 5)
- X-Rider defeats Minotaur. (Ep. 6)
- X-Rider defeats Icarus. (Ep. 7)
- Apollogeist, G.O.D.'s chief of security, arrives in Japan. X-Rider defeats Atlas. (Ep. 8)
- X-Rider defeats Achilles. (Ep. 9)
- X-Rider defeats Prometheus. (Ep. 10)
- X-Rider defeats Hydra. (Ep. 11)
- X-Rider defeats Chimera. (Ep. 12)
- X-Rider defeats Ulysses. (Ep. 13)
- X-Rider defeats Apollogeist. (Ep. 14)
- X-Rider defeats Chronos. (Ep. 15)
- X-Rider defeats Cerberus. (Ep. 16)
- Apollogeist is revived, and X-Rider defeats Alseides. (Ep. 17)
- X-Rider defeats Cateus. (Ep. 18)
- X-Rider defeats Occultos. (Ep. 19)
- X-Rider defeats Salamander-Gong. (Ep. 20)
- X-Rider defeats the Revived Apollogeist. (Ep. 21)
- Kingdark, the leader of G.O.D., makes his appearance known. X-Rider defeats Ghengis Khan-Condor. (Ep. 22)
- X-Rider defeats Toad-Goemon. (Ep. 23)
- X-Rider defeats Scorpion-Geronimo. (Ep. 24)
- X-Rider defeats Horned Beetle-Lupin. (Ep. 25)
- X-Rider defeats Starfish-Hitler. (Ep. 26)
- X-Rider teams up with The Double Riders, Kamen Rider V3 and Riderman in order to defeat a few revived Kaijin and Franken Bat. (Five Riders vs. King Dark)
- X-Rider meets Kamen Rider V3. (Ep. 27)
- Kamen Rider V3 gives X-Rider the Mercury Circuit, which powers him up. X-Rider defeats Spider-Napoleon. (Ep. 28)
- X-Rider defeats Chameleon-Phantom. (Ep. 29)
- X-Rider defeats Leech Dracula. (Ep. 30)
- X-Rider defeats Lizard-Viking. (Ep. 31)
- X-Rider defeats Ant Capone and meets Kamen Rider #2. (Ep. 32)
- X-Rider defeats Centipede Youkihi. (Ep. 33)
- X-Rider defeats Tiger Nero. (Ep. 34)
- X-Rider defeats Scorpion-Geronimo Jr. and King Dark, which is revealed to have been controlled by Dr. Noroi, a former friend of Keitaro Jin. (Ep. 35)
- 1975: Kamen Rider X, alongside the other past riders, assist Kamen Rider Stronger in defeating the Delzer Army, and later it's true leader, General Great Darkness. (Stronger Ep. 39, All Together Seven Kamen Riders)
- 1980: Kamen Rider X, alongside the other past riders, assist Kamen Rider: Skyrider in defeating Galaxy King. Both later assist him on other occasions. (Eight Riders Vs Galaxy King, Kamen Rider Skyrider)
- 1981: Kamen Rider X, alongside the other past riders, assist Kamen Rider Super-1 in fighting some of the Dogma Kingdom's monsters. (Kamen Rider Super-1)
- 1984: Kamen Rider X, alongside the other past riders, assist the new Kamen Rider ZX in defeating the Badam Empire. (Birth of the Tenth! Gather All Kamen Riders!!)
- 1989: Kamen Rider X, alongside the other past riders, assist Kamen Rider BLACK RX in destroying the Crisis Empire. (Black RX Ep. 41-47)
- 2009: Kamen Rider X, alongside the other past riders, assist Kamen Rider Decade in defeating an alternate reality counterpart of Shadow Moon. (All Riders vs. Dai-Shocker)
- 2011:
- Kamen Rider X, alongside the other past riders, assist Kamen Rider OOO in defeating the revived Great Leader of Gel-Shocker. (OOO, Den-O, All Riders: Let's Go Kamen Riders)
- Kamen Rider X, alongside a few other past riders, assist Kamen Rider Fourze and Kamen Rider OOO in defeating Kamen Rider Poseidon and Super Galaxy King. (Kamen Rider × Kamen Rider Fourze & OOO: Movie War Mega Max)
- 2012: Kamen Rider X, among the rest of the Kamen Riders, are apparently defeated by Dai-Zangyack led by Emperor (formerly Captain) Marvelous (Gokai Red) who is hunting the Kamen Riders, while the first 34 Super Sentai are apparently defeated by Tsukasa Kadoya (Kamen Rider Decade), Great Leader of Dai-Shocker which seeks to wipe out the Super Sentai. Infact, all the presumed deceased Sentai and Riders had been transported to a dimensional rift, from which they emerge to defeat the new Shocker-Zangyack Alliance. (Kamen Rider × Super Sentai: Super Hero Taisen)
- 2014: Kamen Rider X, along with other past riders and with the help of Kyoryu Red and the ToQgers, finally defeat the Badam Empire. (Heisei Rider vs. Showa Rider: Kamen Rider Taisen feat. Super Sentai)
- 2015: Kamen Rider X, alongside the other past riders, assist Kamen Rider Drive in defeating the revived Great Leader of Gel-Shocker. (Super Hero Taisen GP: Kamen Rider #3)
- 2021: Kamen Rider X, along with other past riders and Sentai warriors, assist Kamen Rider Saber's riders and Kikai Sentai Zenkaiger in defeating Asmodeus. (Kamen Rider Saber + Kikai Sentai Zenkaiger Super Hero Senki)
