1 | Bulbasaur | Blue | Starter2 | Ivysaur | Blue | Evolve Bulbasaur (Lv. 16) | 3 | Venusaur | Blue | Evolve Ivysaur (Lv. 32) | 4 | Charmander | Blue | Starter | 5 | Charmeleon | Blue | Evolve Charmander (Lv. 16) | 6 | Charizard | Blue | Evolve Charmeleon (Lv. 36) | 7 | Squirtle | Blue | Starter | 8 | Wartortle | Blue | Evolve Squirtle (Lv. 16) | 9 | Blastoise | Blue | Evolve Wartortle (Lv. 36) | 10 | Caterpie | Blue | Routes 2, 24, 25, Viridian Forest | 11 | Metapod | Blue | Routes 24, 25, Viridian Forest | 12 | Butterfree | Blue | Evolve Metapod (Lv. 10) | 13 | Weedle | Blue | Route 25, Viridian Forest | 14 | Kakuna | Blue | Route 25, Viridian Forest | 15 | Beedrill | Blue | Evolve Kakuna (Lv. 10) | 16 | Pidgey | Blue | Routes 1, 2, 3, 5, 6, 7, 8, 12, 13, 14, 15, 21, 24, 25 | 17 | Pidgeotto | Blue | Routes 14, 15, 21 | 18 | Pidgeot | Blue | Evolve Pidgeotto (Lv. 36) | 19 | Rattata | Blue | Routes 1, 2, 4, 9, 16, 21, 22 | 20 | Raticate | Blue | Routes 16, 17, 18, 21 | 21 | Spearow | Blue | Routes 3, 4, 9, 10, 11, 16, 17, 18, 22, 23 | 22 | Fearow | Blue | Routes 17, 18, 23 | 23 | Ekans | Blue | Trade | 24 | Arbok | Blue | Trade | 25 | Pikachu | Blue | Viridian Forest, Power Plant | 26 | Raichu | Blue | Power Plant, Cerulean Cave | 27 | Sandshrew | Blue | Routes 4, 8, 9, 10, 11, 23 | 28 | Sandslash | Blue | Route 23, Cerulean Cave | 29 | NidoranF | Blue | Route 22, Safari Zone | 30 | Nidorina | Blue | Safari Zone
| Trade Nidorino on Route 11 31 | Nidoqueen | Blue | Evolve Nidorina (Moon Stone) | 32 | NidoranM | Blue | Route 22, Safari Zone | 33 | Nidorino | Blue | Safari Zone, Celadon Game Corner | 34 | Nidoking | Blue | Evolve Nidorino (Moon Stone) | 35 | Clefairy | Blue | Mt. Moon, Celadon City (Rocket Game Corner) | 36 | Clefable | Blue | Evolve Clefairy (Moon Stone) | 37 | Vulipx | Blue | Routes 7, 8, Pokemon Mansion | 38 | Ninetales | Blue | Evolve Vulpix (Fire Stone) | 39 | Jigglypuff | Blue | Route 3 | 40 | Wigglytuff | Blue | Cerulean Cave | 41 | Zubat | Blue | Mt. Moon, Rock Tunnel, Seafoam Islands, Victory Road | 42 | Golbat | Blue | Seafoam Islands, Victory Road, Cerulean Cave | 43 | Oddish | Blue | Trade | 44 | Gloom | Blue | Trade | 45 | Vileplume | Blue | Trade | 46 | Paras | Blue | Mt. Moon, Safari Zone | 47 | Parasect | Blue | Safari Zone, Cerulean Cave | 48 | Venonat | Blue | Routes 12, 13, 14, 15, Safari Zone | 49 | Venomoth | Blue | Safari Zone, Victory Road, Cerulean Cave | 50 | Diglett | Blue | Diglett's Cave | 51 | Dugtrio | Blue | Diglett's Cave | 52 | Meowth | Blue | Routes 5, 6, 7, 8 | 53 | Persian | Blue | Evolve Meowth (Lv. 28) | 54 | Psyduck | Blue | Seafoam Islands
| Routes 24, 25, Cerulean City, Cerulean Gym, Safari Zone (Super Rod) 55 | Golduck | Blue | Seafoam Islands | 56 | Mankey | Blue | Trade | 57 | Primeape | Blue | Trade | 58 | Growlithe | Blue | Trade | 59 | Arcanine | Blue | Trade | 60 | Poliwag | Blue | Routes 6, 10, 11, 12, 13, 17, 18, 19, 20, 21, 22, 23, 24, 25, Pallet Town, Viridian City, Cerulean City, Cerulean Gym, Cerulean Cave, Vermilion City, Celadon City, Fuchsia City, Safari Zone, Seafoam Islands, Cinnabar Island, Indigo Plateau (Good Rod)
| Pallet Town, Viridian City, Route 22 (Super Rod) 61 | Poliwhirl | Blue | Route 10, Celadon City (Super Rod) | 62 | Poliwrath | Blue | Evolve Poliwhirl (Water Stone) | 63 | Abra | Blue | Routes 24, 25, Celadon City (Rocket Game Corner) | 64 | Kadabra | Blue | Cerulean Cave | 65 | Alakazam | Blue | Evolve Kadabra (Trade) | 66 | Machop | Blue | Rock Tunnel, Victory Road | 67 | Machoke | Blue | Victory Road | 68 | Machamp | Blue | Evolve Machoke (Trade) | 69 | Bellsprout | Blue | Routes 5, 6, 7, 12, 13, 14, 15, 24, 25 | 70 | Weepinbell | Blue | Routes 12, 13, 14, 15 | 71 | Victreebel | Blue | Evolve Weepinbell (Leaf Stone) | 72 | Tentacool | Blue | Routes 19, 20, 21 (Surfing)
| Routes 12, 13, 17, 18, Pallet Town, Viridian City (Super Rod) 73 | Tentacruel | Blue | Evolve Tentacool (Lv. 30) | 74 | Geodude | Blue | Mt. Moon, Rock Tunnel, Victory Road | 75 | Graveler | Blue | Victory Road | 76 | Golem | Blue | Evolve Graveler (Trade) | 77 | Ponyta | Blue | Pokemon Mansion | 78 | Rapidash | Blue | Evolve Ponyta (Lv. 40) | 79 | Slowpoke | Blue | Seafoam Islands
Route 10, Celadon City, Safari Zone (Super Rod) | 80 | Slowbro | Blue | Route 23, Cerulean Cave (Super Rod)
Seafoam Islands (Walking) | 81 | Magnemite | Blue | Power Plant | 82 | Magneton | Blue | Power Plant, Cerulean Cave | 83 | Farfetch'd | Blue | Trade Spearow in Vermillion City | 84 | |