The short answer is Mew, and it is not close. This page counts how many different moves each Pokémon in the pokee.si Pokédex can learn, using the level-up, TM, egg and tutor lists on its page, plus reviewed reminder-only entries where available. Mew's list is nearly twice as long as the next one.
How we counted
Each Pokémon page shows the moves from the most recent game that has the Pokémon. That is Scarlet and Violet for most of them, Sword and Shield for some, and Ultra Sun and Ultra Moon for a few. Of the 1,025 Pokémon, 733 show Scarlet and Violet, 244 show Sword and Shield and 48 show Ultra Sun and Ultra Moon. The middle Pokémon in Scarlet and Violet has 56 different moves.
A move that appears in two lists counts once. That is why a Pokémon's method columns can add up to more than the last number.
Three limits matter. First, tutor moves exist in Sword and Shield and Ultra Sun and Ultra Moon but hardly at all in Scarlet and Violet, so a Pokémon from an older game is not a fair match for one from a newer game. Second, reminder-only entries have been reviewed for Dipplin, Ogerpon and Hydrapple; this is not a complete review for every species. A dash in the Reminder column means it has not been reviewed here. Third, our egg-move lists are longer than Pokémon Database's for some evolved Pokémon: it shows none for Shiftry or Clefable in Scarlet and Violet, where our data shows 23 and 21. We checked Mew, Arceus, Gallade and Mr. Rime against Pokémon Database, and the level-up and TM numbers match, with one move different for Gallade and Mr. Rime each.
The top of Scarlet and Violet
| # | Pokémon | Level-up | TM | Egg | Tutor | Reminder | Different moves |
|---|---|---|---|---|---|---|---|
| 1 | Mew | 12 | 229 | 0 | 0 | — | 234 |
| 2 | Arceus | 12 | 114 | 0 | 0 | — | 121 |
| 3 | Gallade | 33 | 88 | 8 | 0 | — | 113 |
| 4 | Mewtwo | 16 | 91 | 0 | 0 | — | 102 |
| 5 | Wigglytuff | 21 | 81 | 8 | 0 | — | 100 |
| 6 | Shiftry | 5 | 73 | 23 | 0 | — | 97 |
| 7 | Jigglypuff | 20 | 77 | 8 | 0 | — | 96 |
| 8 | Clefable | 4 | 76 | 21 | 0 | — | 95 |
| 9 | Slaking | 14 | 79 | 9 | 0 | — | 95 |
| 10 | Infernape | 14 | 79 | 12 | 0 | — | 94 |
| 11 | Clefairy | 21 | 72 | 4 | 0 | — | 91 |
| 12 | Rhyperior | 16 | 78 | 6 | 0 | — | 91 |
Mew has 12 level-up moves and every TM, and no egg or tutor moves. Arceus, Mewtwo and Gallade follow, and after that the lists are close to each other. Dudunsparce also reaches 91 and just misses the table. Mew leads second place by 113 moves, and its total is about 4.2 times the middle Pokémon's.
Because the egg lists are the weak spot, here is the same ranking with egg moves removed.
| # | Pokémon | Level-up and TM moves |
|---|---|---|
| 1 | Mew | 234 |
| 2 | Arceus | 121 |
| 3 | Gallade | 107 |
| 4 | Mewtwo | 102 |
| 5 | Wigglytuff | 94 |
| 6 | Jigglypuff | 90 |
| 7 | Slaking | 89 |
| 8 | Infernape | 88 |
Other games
Pokémon whose latest game is Sword and Shield or Ultra Sun and Ultra Moon cannot be compared to the table above. Here are the leaders in each.
Sword and Shield:
| # | Pokémon | Level-up | TM | Egg | Tutor | Reminder | Different moves |
|---|---|---|---|---|---|---|---|
| 1 | Mr. Rime | 30 | 69 | 5 | 2 | — | 93 |
| 2 | Nidoking | 15 | 72 | 10 | 1 | — | 91 |
| 3 | Aggron | 17 | 70 | 6 | 3 | — | 89 |
| 4 | Pangoro | 17 | 67 | 5 | 2 | — | 85 |
| 5 | Obstagoon | 22 | 64 | 3 | 1 | — | 84 |
Ultra Sun and Ultra Moon:
| # | Pokémon | Level-up | TM | Egg | Tutor | Reminder | Different moves |
|---|---|---|---|---|---|---|---|
| 1 | Kecleon | 19 | 37 | 12 | 25 | — | 83 |
| 2 | Watchog | 23 | 31 | 9 | 22 | — | 77 |
| 3 | Spinda | 13 | 30 | 17 | 22 | — | 76 |
| 4 | Bibarel | 18 | 36 | 13 | 14 | — | 73 |
| 5 | Skitty | 19 | 33 | 14 | 12 | — | 69 |
In Ultra Sun and Ultra Moon, the top three get 22 to 25 of their moves from tutors. In Scarlet and Violet our data holds only 4 tutor moves in total.
Level-up, TM and egg leaders
| List | Scarlet and Violet leaders | Sword and Shield leaders |
|---|---|---|
| Level-up | Gallade 33, Snorlax 27, Lucario 26 | Mr. Rime 30, Steelix 24, Ninjask 23 |
| TM (TR in Sword and Shield) | Mew 229, Arceus 114, Mewtwo 91 | Nidoking 72, Nidoqueen 71, Aggron 70 |
| Egg, as listed in our data | Shiftry 23, Clefable 21, Ludicolo 18 | Farfetch'd 13, Sirfetch'd 13, Nidoran♂ 10 |
Every one of the 229 TMs in Scarlet and Violet is on Mew's list, which is why it leads the TM row by so much.
The Pokémon with the fewest moves
| Pokémon | Different moves | What it learns |
|---|---|---|
| Ditto | 1 | Transform |
| Unown | 1 | Hidden Power |
| Smeargle | 1 | Sketch |
| Cosmog | 2 | Splash, Teleport |
| Cosmoem | 2 | Cosmic Power, Teleport |
| Metapod | 3 | Harden, Electroweb, Iron Defense |
| Magikarp | 3 | Splash, Tackle, Flail |
Smeargle is the odd one. Its list holds Sketch and nothing else, but Pokémon Database says Sketch permanently copies the last move the target used, then disappears. Smeargle can end up with a very wide range of moves. Ditto has Transform, and Magikarp has Splash, Tackle and Flail.
Which moves almost everyone can learn
In Scarlet and Violet, these moves are learned by the most Pokémon, out of 733: Tera Blast 726, Protect 722, Substitute 719, Endure 718, Sleep Talk 718, Rest 717. Tera Blast tops the list, and Protect, Substitute and Rest are close behind.
What a long list means
A long list gives choice, but it says nothing about how strong the moves are. For how attacks gain power from the user's type, read what STAB means.