| # | Pokémon | Element | Location |
| A | |||
| 63 | Abra | Psychic | Celadon Game Corner in Red for 180, in Blue for 120 coins, Route 24, 25 |
| 142 | Aerodactyl | Rock/Flying | Give the Old Amber to guy in Pokémon Lab |
| 65 | Alakazam | Psychic | Evolves from Kadabra by trade |
| 24 | Arbok | Poison | Evolves from Ekans at Lv22, Unknown Dungeon, Route 23 |
| 59 | Arcanine | Fire | Evolves from Growlithe with use of a Fire Stone |
| 144 | Articuno | Ice/Flying | Seafoam Islands |
| B | |||
| 15 | Beedrill | Bug/Poison | Evolves from Kakuna at Lv10 |
| 69 | Bellsprout | Grass/Poison | Only Blue: Route 5, 6, 7, 8, 12, 13, 14, 15, 24, 25 |
| 9 | Blastoise | Water | Evolves from Wartortle at Lv36 |
| 1 | Bulbasaur | Grass/Poison | Prof. Oak's Lab |
| 12 | Butterfree | Bug/Flying | Evolves from Metapod at Lv10 |
| C | |||
| 10 | Caterpie | Bug | Viridian Forest, Route 2, 24, 25 |
| 113 | Chansey | Normal | Safari Zone, Unknown Dungeon |
| 6 | Charizard | Fire/Flying | Evolves from Charmeleon at Lv36 |
| 4 | Charmander | Fire | Prof. Oak's Lab |
| 5 | Charmeleon | Fire | Evolves from Charmander at Lv16 |
| 36 | Clefable | Normal | Evolves from Clefairy with use of a Moon Stone |
| 35 | Clefairy | Normal | Mt. Moon, Celadon Game Corner in Red for 500, in Blue for 750 coins |
| 91 | Cloyster | Water/Ice | Evolves from Shellder with use of a Water Stone |
| 104 | Cubone | Ground | Lavender Town Pokémon Tower |
| D | |||
| 87 | Dewgong | Water/Ice | Evolves from Seel at Lv34, Seafoam Islands |
| 50 | Diglett | Ground | Diglett's Cave |
| 132 | Ditto | Normal | Route 13, 14, 15, 23, Unknown Dungeon |
| 85 | Dodrio | Normal/Flying | Evolves from Doduo at Lv31, Unknown Dungeon |
| 84 | Doduo | Normal/Flying | Safari Zone, Route 16, 17, 18 |
| 148 | Dragonair | Dragon | Evolves from Dratini at Lv30 |
| 149 | Dragonite | Dragon | Evolves from Dragonair at Lv55 |
| 147 | Dratini | Dragon | Safari Zone (Fish with Super Rod), Celadon City Game Corner in Red for 2.800, in Blue for 4.600 coins |
| 96 | Drowzee | Psychic | Route 11 |
| 51 | Dugtrio | Ground | Evolves from Diglett at Lv26, Diglett's Cave |
| E | |||
| 133 | Eevee | Normal | Top Floor of Celadon City Mansion (enter through back door) |
| 23 | Ekans | Poison | Only Red: Route 4, 8, 9, 11, 23 |
| 125 | Electabuzz | Electric | Only Red: Power Plant |
| 101 | Electrode | Electric | Evolves from Voltorb at Lv30 Unknown Dungeon |
| 102 | Exeggcute | Grass/Psychic | Safari Zone |
| 103 | Exeggutor | Grass/Psychic | Evolves from Exeggcute with use of a Leaf Stone |
| F | |||
| 83 | Farfetche'd | Normal/Flying | Vermillion City, trade for Spearow |
| 22 | Fearow | Normal/Flying | Evolves from Fearow at Lv20, Route 16, 17, 18, 23 |
| 136 | Flareon | Fire | Evolves from Eevee with use of a Fire Stone |
| G | |||
| 92 | Gastly | Ghost/Poison | Lavender Pokémon Tower |
| 94 | Gengar | Ghost/Poison | Evolves from Haunter when traded |
| 74 | Geodude | Rock/Ground | Mt. Moon, Rock Tunnel, Victory Road |
| 44 | Gloom | Grass/Poison | Evolves from Oddish at Lv21, Route 13, 14, 15 (only Red) |
| 42 | Golbat | Poison/Flying | Evolves from Zubat at Lv22, Route 23, Seafoam Islands, Victory Road |
| 118 | Goldeen | Water | Cerulean Gym, Fuchsia, Cinnabar Island, Route 4, 12, 13, 17, 18, 19, 20, 21, 24, 25 (fish for it) |
| 55 | Golduck | Water | Evolves from Psyduck at Lv33, Seafoam Islands |
| 76 | Golem | Rock/Ground | Evolves from Geodude when traded |
| 75 | Graveler | Rock/Ground | Evolves from Geodude at Lv25, Victory Road |
| 88 | Grimer | Poison | Cinnabar Island Pokémon Mansion |
| 58 | Growlithe | Fire | Red Only: Route 7, 8, Cinnabar Island Pokémon Mansion |
| 130 | Gyarados | Water/Flying | Evolves from Magikarp at Lv20 |
| H | |||
| 93 | Haunter | Ghost/Poison | Evolves from Gastly at Lv25, Lavender Pokémon Tower |
| 107 | Hitmonchan | Fighting | Saffron City Dojo |
| 106 | Hitmonlee | Fighting | Saffron City Dojo |
| 116 | Horsea | Water | Seafoam Islands, Cinnabar Island, Route 19, 20, 21 |
| 97 | Hypno | Psychic | Evolves from Drowzee at Lv26, Unknown Dungeon |
| I | |||
| 2 | Ivysaur | Grass/Poison | Evolves from Bulbasaur at Lv16 |
| J | |||
| 39 | Jigglypuff | Normal | Route 3 |
| 135 | Jolteon | Electric | Evolves from Eevee with use of a Thunder Stone |
| 124 | Jynx | Ice/Psychic | Trade for Poliwhirl in Cerulean City |
| K | |||
| 140 | Kabuto | Rock/Water | Give man in Cinnabar Lab the Dome Fossil |
| 141 | Kabutops | Rock/Water | Evolves from Kabuto at Lv40 |
| 64 | Kadabra | Psychic | Evolves from Abra at Lv16, Unknown Dungeon |
| 14 | Kakuna | Bug/Poison | Evolves from Weedle at Lv7, Viridian Forest, Route 24, 25 |
| 115 | Kangaskhan | Normal | Safari Zone |
| 99 | Kingler | Water | Evolves from Krabby at Lv28, Seafoam Islands, Unknown Dungeon, Route 23 |
| 109 | Koffing | Poison | Cinnabar Island Pokémon Mansion |
| 98 | Krabby | Water | Cerulean, Vermillion, Fuchsia, Safari Zone, Seafoam Islands, Cinnabar, Route 6, 11, 12, 13, 24, 25 |
| L | |||
| 131 | Lapras | Water/Ice | Silph Co. |
| 108 | Lickitung | Normal | Trade for on Route 18 |
| M | |||
| 68 | Machamp | Fighting | Evolves from Machoke when traded |
| 67 | Machoke | Fighting | Evolves from Machop at Lv28, Victory Road |
| 66 | Machop | Fighting | Rock Tunnel, Victory Road |
| 129 | Magikarp | Water | Fish anywhere with an Old Rod |
| 126 | Magmar | Fire | Only Blue: Cinnabar Island Pokémon Mansion |
| 81 | Magnemite | Electric | Power Plant |
| 82 | Magenton | Electric | Evolves from Magnemite at Lv30, Power Plant, Unknown Dungeon |
| 56 | Mankey | Fighting | Only Red: Route 5, 6, 7, 8 |
| 105 | Marowak | Ground | Evolves from Cubone at Lv28, Unknown Dungeon |
| 52 | Meowth | Normal | Only Blue: Route 5, 6, 7, 8 |
| 11 | Metapod | Bug | Evolves from Caterpie at Lv7, Route 24, 25, Viridian Forest |
| 151 | Mew | Psychic | Nintendo Download Events, Gameshark |
| 150 | Mewtwo | Psychic | Unknown Dungeon |
| 146 | Moltres | Fire | Victory Road |
| 122 | Mr Mime | Psychic | Trade for Abra on Route 2 |
| 89 | Muk | Poison | Evolves from Grimer at Lv38, Cinnabar Island Pokeacute;mon Mansion |
| N | |||
| 34 | Nidoking | Poison/Ground | Evolves from Nidorino with use of a Moon Stone |
| 31 | Nidoqueen | Poison/Ground | Evolves from Nidorina with use of a Moon Stone |
| 29 | Nidoran(f) | Poison | Safari Zone, Route 22 |
| 32 | Nidoran(m) | Poison | Safari Zone, Route 22 |
| 30 | Nidorina | Poison | Evolves from Nidoran(f) at Lv16, Safari Zone, Only Red: Celadon Game Corner for 1200 coins |
| 33 | Nidorino | Poison | Evolves from Nidoran(m) at Lv16, Safari Zone, Only Blue: Celadon Game Corner for 1200 coins |
| 38 | Ninetales | Fire | Evolves from Vulpix with use of a Fire Stone |
| O | |||
| 43 | Oddish | Grass/Poison | Only Red. Route 5, 8, 12, 13, 14, 15, 24, 25 |
| 138 | Omanyte | Rock/Water | Give man in Cinnabar Island Helix Fossil |
| 139 | Omastar | Rock/Water | Evolves from Omanyte at Lv40 |
| 95 | Onix | Rock/Ground | Rock Tunnel, Victory Road |
| P | |||
| 46 | Paras | Bug/Grass | Mt. Moon, Safari Zone |
| 47 | Parasect | Bug/Grass | Evolves from Paras at Lv24, Safari Zone, Unknown Dungeon |
| 53 | Persian | Normal | Evolves from Meowth at Lv28 |
| 18 | Pidgeot | Normal/Flying | Evolves from Pidgeotto at Lv36 |
| 17 | Pidgeotto | Normal/Flying | Evolves from Pidgey at Lv18, Route 14, 15, 21 |
| 16 | Pidgey | Normal/Flying | Route 1, 2, 3, 5, 7, 8, 12, 13, 14, 15, 21, 24, 25 |
| 25 | Pikachu | Electric | Viridian Forest, Power Plant |
| 127 | Pinsir | Bug | Only Blue: Safari Zone, Celadon Game Corner for 2500 coins |
| 60 | Poliwag | Water | Pallet Town, Viridian City, Cerulean City, Vermillion City, Route 22 |
| 61 | Poliwhirl | Water | Evolves from Poliwag at Lv25, Celadon City, Route 9, 10 |
| 62 | Poliwrath | Water/Fighting | Evolves from Poliwhirl with use of a Water Stone |
| 77 | Ponyta | Fire | Cinnabar Island Pokémon Mansion |
| 137 | Porygon | Normal | Celadon City Game Corner in Red for 9999, in Blue for 6500 coins |
| 57 | Primeape | Fighting | Evolves from Mankey at Lv28 |
| 54 | Psyduck | Water | Safari Zone, Seafoam Island |
| Q | |||
| R | |||
| 26 | Raichu | Electric | Evolves from Pikachu with use of a Thunder Stone, Unknown Dungeon, In Blue at Power Plant |
| 78 | Rapidash | Fire | Evolves fropm Ponyta at Lv40 |
| 20 | Raticate | Normal | Evolves from Rattata at Lv20, Route 16, 17, 18, 21 |
| 19 | Rattata | Normal | Route 1, 2, 4, 9, 14, 15, 16, 17,18, 21, 22 |
| 112 | Rhydon | Rock/Ground | Evolves from Rhyhorn at Lv42, Unknown Dungeon |
| 111 | Rhyhorn | Rock/Ground | Safari Zone |
| S | |||
| 26 | Sandshrew | Ground | Only Blue: Route 4, 8, 9, 10, 11, 23 |
| 27 | Sandslash | Ground | Evolves from Sandshrew at Lv22 Only Blue: Unknown Dungeon, Route 23 |
| 123 | Scyther | Bug/Flying | Safari Zone |
| 117 | Seadra | Water | Evolves from Horsea at Lv32, Seafoam Islands, Unknown Dungeon, Route 23 |
| 119 | Seaking | Water | Fuchsia, Unknown Dungeon, Route 23 (fishing) |
| 86 | Seel | Water | Seafoam Islands |
| 90 | Shellder | Water | Seafoam Islands, Route 19, 20, 21 |
| 80 | Slowbro | Water/Psychic | Evolves from Slowpoke at Lv37, Seafoam Islands |
| 79 | Slowpoke | Water/Psychic | Seafoam Islands |
| 143 | Snorlax | Normal | Route 12, 16 |
| 21 | Spearow | Normal | Route 3, 4, 9, 11, 16, 17, 18, 21, 22, 23 |
| 7 | Squirtle | Water | Prof. Oaks Lab |
| 121 | Starmie | Water | Evolves from Starmie with use of a Water Stone |
| 120 | Staryu | Water | Seafoam Islands, Cinnabar Island, Route 19, 20, 21 |
| T | |||
| 114 | Tangela | Grass | Route 21 |
| 128 | Tauros | Normal | Safari Zone |
| 72 | Tentacool | Water/Poison | Pallet Town, Viridian City, Route 12, 13, 16, 17, 18, 19, 20, 21 |
| 73 | Tentacruel | Water/Poison | Evolves from Tentacool at Lv30 |
| U | |||
| V | |||
| 134 | Vaporeon | Water | Evolves from Eevee with use of a Water Stone |
| 49 | Venomoth | Bug/Poison | Evolves from Venonat at Lv31, Safari Zone, Victory Road, Unknown Dungeon |
| 48 | Venonat | Bug/Poison | Safari Zone, Route 13, 14, 15 |
| 3 | Venusaur | Grass/Poison | Evolves from Ivysaur at Lv32 |
| 71 | Victreebell | Grass/Poison | Evolves from Weepinbell with use of a Leaf Stone |
| 100 | Voltorb | Electric | Power Plant, Route 9 |
| 37 | Vulpix | Fire | Only Blue: Cinnabar Island Pokémon Mansion, Route 7, 8 |
| W | |||
| 8 | Wartortle | Water | Evolves from Squirtle at Lv16 |
| 13 | Weedle | Bug/Poison | Viridian Forest, Route 2, 24, 25 |
| 70 | Weepinbell | Grass/Poison | Evolves from Bellsprout at Lv21, Route 12, 13, 14, 15 |
| 110 | Weezing | Poison | Evolves from Koffing at Lv35, Cinnabar Island Pokémon Mansion |
| 40 | Wigglytuff | Normal | Evolves from Jigglypuff with use of a Moon Stone, Unknown Dungeon |
| X | |||
| Y | |||
| Z | |||
| 145 | Zapdos | Electric | Power Plant |
| 41 | Zubat | Poison/Flying | Mt. Moon, Rock Tunnel, Seafoam Islands, Victory Road |