Kanto:
* Brock (Pewter City): Rock-type
* Misty (Cerulean City): Water-type
* Lt. Surge (Vermilion City): Electric-type
* Erika (Celadon City): Grass-type
* Koga (Fuchsia City): Poison-type
* Sabrina (Saffron City): Psychic-type
* Gary Oak (Viridian City): Initially a rival, Gary later became the Viridian City Gym Leader in the anime.
* Giovanni (Silph Co.): Giovanni is the leader of Team Rocket and the Viridian City Gym Leader in the anime. He's a Ground-type specialist.
Johto:
* Falkner (New Bark Town): Flying-type
* Bugsy (Azalea Town): Bug-type
* Whitney (Goldenrod City): Normal-type
* Morty (Ecruteak City): Ghost-type
* Chuck (Cianwood City): Fighting-type
* Jasmine (Olivine City): Steel-type
* Pryce (Mahogany Town): Ice-type
* Clair (Blackthorn City): Dragon-type
Hoenn:
* Norman (Petalburg City): Normal-type
* Brawly (Dewford Town): Fighting-type
* Winona (Slateport City): Flying-type
* Tate & Liza (Fortree City): Dragon-type (Double battle)
* Juan (Mossdeep City): Water-type
* Flannery (Lavaridge Town): Fire-type
* Maylene (Veilstone City): Fighting-type
* Crasher Wake (Pastoria City): Water-type
* Fantina (Hearthome City): Ghost-type
* Byron (Canalave City): Steel-type
* Lucian (Sunyshore City): Ghost-type
Sinnoh:
* Roark (Oreburgh City): Rock-type
* Gardenia (Eterna City): Grass-type
* May (Veilstone City): Normal-type (She is a Gym Leader in the anime, but not in the games)
* Crasher Wake (Pastoria City): Water-type (He is a Gym Leader in the anime, but not in the games)
* Barry (Twinleaf Town): Normal-type (He is a Gym Leader in the anime, but not in the games)
* Fantina (Hearthome City): Ghost-type
* Byron (Canalave City): Steel-type
* Candice (Snowpoint City): Ice-type
* Volkner (Sunyshore City): Electric-type
Unova:
* Cilan (Striaton City): Grass-type
* Chili (Striaton City): Fire-type
* Cress (Striaton City): Water-type
* Lenora (Nacrene City): Normal-type
* Burgh (Castelia City): Bug-type
* Elesa (Nimbasa City): Electric-type
* Clay (Driftveil City): Ground-type
* Skyla (Cloudsdale City): Flying-type
* Marlon (Icirrus City): Ice-type
* Shauntal (Undella Bay): Ghost-type
* Iris (Dragonspiral Tower): Dragon-type
* Drayden (Opelucid City): Dragon-type
Kalos:
* Viola (Santalune City): Bug-type
* Grant (Lumiose City): Rock-type
* Korrina (Shalour City): Fighting-type
* Ramos (Cyllage City): Grass-type
* Olympia (Anistar City): Psychic-type
* Wulfric (Snowbelle City): Ice-type
* Valerie (Coumarine City): Fairy-type
Note: The Gym Leaders featured in the anime may not always align with the games, as the anime sometimes takes creative liberties with the stories.