Pokémon evolutions by trading

This is a list of Pokémon that evolve by trading. The classic four evolutions (Alakazam, Machoke, Graveler and Gengar) from Red/Blue/Yellow evolve only by trading, while most Pokémon from later generations require an item to be held in addition.

This information applies to any games that feature both Pokémon from the chain, so for example in Generation 1 the evolution chain with Steelix doesn't exist.

The Pokémon

Evolving from
Evolving to
Hold item/condition
Poliwhirl Poliwhirl → Politoed Politoed Kings Rock
Kadabra Kadabra → Alakazam Alakazam
Machoke Machoke → Machamp Machamp
Graveler Graveler → Golem Golem
Alolan Graveler Graveler
Alolan Graveler 		→ Alolan Golem Golem
Alolan Golem
Slowpoke Slowpoke → Slowking Slowking Kings Rock
Haunter Haunter → Gengar Gengar
Onix Onix → Steelix Steelix Metal Coat
Rhydon Rhydon → Rhyperior Rhyperior Protector
Seadra Seadra → Kingdra Kingdra Dragon Scale
Scyther Scyther → Scizor Scizor Metal Coat
Electabuzz Electabuzz → Electivire Electivire Electirizer
Magmar Magmar → Magmortar Magmortar Magmarizer
Porygon Porygon → Porygon2 Porygon2 Upgrade
Porygon2 Porygon2 → Porygon-Z Porygon-Z Dubious Disc
Feebas Feebas → Milotic Milotic Prism Scale, or level up with max Beauty
Dusclops Dusclops → Dusknoir Dusknoir Reaper Cloth
Clamperl Clamperl → Huntail Huntail Deep Sea Tooth
Clamperl Clamperl → Gorebyss Gorebyss Deep Sea Scale
Boldore Boldore → Gigalith Gigalith
Gurdurr Gurdurr → Conkeldurr Conkeldurr
Karrablast Karrablast → Escavalier Escavalier Trade with Shelmet
Shelmet Shelmet → Accelgor Accelgor Trade with Karrablast
Spritzee Spritzee → Aromatisse Aromatisse Sachet
Swirlix Swirlix → Slurpuff Slurpuff Whipped Dream
Phantump Phantump → Trevenant Trevenant
Pumpkaboo (Average Size) Pumpkaboo
Average Size 		→ Gourgeist (Average Size) Gourgeist
Average Size