A list of Franchise/{{Pokemon}} who debuted in ''VideoGame/PokemonRedAndBlue'', along with their relatives.

The original generation, at 151 Pokémon, was the largest one until [[VideoGame/PokemonBlackAndWhite Generation V]] surpassed it. However, due to the introduction of many relatives of Pokémon of this gen in ''VideoGame/PokemonGoldAndSilver'' and ''VideoGame/PokemonDiamondAndPearl'', it is technically the largest gen, as a total of 183 Pokémon are originally from this gen or are an evolutionary relative, and another 2 have very close ties with Pokémon introduced here.

In terms of character design, a good number of them resemble [[EverythingsBetterWithDinosaurs dinosaurs]] or {{Kaiju}} that have been scaled down. Others were designed to be clearly visible as tiny sprites on a monochromatic UsefulNotes/{{Gameboy}} and thus have no more then three or four shades. Many are rounded, almost spherical in some species. Quite a few of the Generation I monsters are iconic enough that they end up influencing the designs of Pokémon from later generations. [[VideoGame/PokemonRedAndBlue Generation I]] introduced some of the patterns now taken for granted: [[GreenThumb Grass]]/[[PlayingWithFire Fire]]/[[MakingASplash Water]] starters, [[ComMons early game bugs, birds, and mammals]], an [[ShockAndAwe Electric]] [[RidiculouslyCuteCritter rodent]], [[FossilRevival part Rock fossils]], [[PowerTrio a legendary trio]], [[InfinityMinusOneSword a 3-stage family with a late evolution and stats that are comparable to legendaries]], [[OlympusMons a bonus legendary with stats beyond anything in the game]], and a secret Pokémon [[DownloadableContent not obtainable via normal ways]] and with [[JackOfAllStats balanced]] [[GameBreaker high stats]]; all originate from here.

For other generations, [[Characters/{{Pokemon}} go here]].
* [[Characters/PokemonGenerationIBulbasaurToTentacruel Bulbasaur to Tentacruel (1-73)]]
* [[Characters/PokemonGenerationIGeodudeToBlissey Geodude to Blissey (74-113)]]
* [[Characters/PokemonGenerationITangelaToMew Tangela to Mew (and Missingno.) (114-151)]]