Head-to-head
Mewtwo vs Mew
The original cloned legendary vs the original mythical it was cloned from.
Side-by-side
Mewtwo
Psychic/None · #0150
BST: 680
Mew
Psychic/None · #0151
BST: 600
Verdict
Winner: Mewtwo
Pure stats favor Mewtwo decisively (680 BST vs 600 BST). Mega Mewtwo Y is the highest-stat Pokémon ever released.
Context: why this matchup matters
Mew is the 151st Pokémon — the legendary 'mythical' that was added as a hidden bonus in Gen 1 (cartridge included unintentionally via a save-file overflow exploit). Mewtwo is Mew's genetically-enhanced clone, created by Team Rocket in the games' lore. Mewtwo is in Ubers; Mew is in OU/UU.
Stat battle: who has the numbers?
Mewtwo: 106/110/90/154/90/130 BST 680. Highest non-mega special attacker stats in the game's first 5 generations. Mew: 100/100/100/100/100/100 BST 600. Perfectly balanced — Mew can learn nearly every TM in the game, the Hidden Ability that turns Power Splits into stat-share, and is one of the few Pokémon that can run ANY role (sweeper, wall, support, lead).
Mega Mewtwo Y (780 BST: 106/150/70/194/120/140) is the highest BST Pokémon ever released. Mega Mewtwo X (780 BST: 106/190/100/154/100/130) is the highest physical attack stat ever released. Mew has no Mega form.
Full matchup analysis
1-on-1 matchup: Mewtwo wins via raw stat advantage. Choice Specs Psystrike OHKOes Mew (Mewtwo's signature move attacks the defender's physical Defense instead of Sp. Def, bypassing Mew's special bulk).
Counter-play for Mew: Synchronize ability lets Mew bounce paralysis/sleep/burn back. Transform (Mew's signature move) lets it copy Mewtwo's stats and moves — but Choice Specs locks Mewtwo into one move anyway, so Transform Mew can mirror. Realistically, even with optimal play, Mew loses 1-on-1.
The 'who's stronger in lore' question: Mewtwo was designed to be a perfect biological weapon, with all of Mew's genetic potential weaponized and amplified. Mew has all 150 Pokémon's DNA in its body, theoretically meaning Mew could mimic any Pokémon. Game Freak has hinted that Mew is the 'ancestor of all Pokémon' — making it potentially more powerful in lore than gameplay implies.
When to pick each
Pick Mewtwo for: Ubers competitive play (it's tier-defining in restricted formats), Specs Psystrike nukes, Calm Mind setup sweeping, Self-Destruct meme builds. Mega Mewtwo Y is the strongest special attacker the game has ever released.
Pick Mew for: OU/UU competitive play (Mewtwo is Ubers-banned in most formats), Stealth Rock + Defog leads, Transform meme builds, status-spreading utility (Will-O-Wisp + Taunt + Roost). Mew's universal learnset means it can fill any role on a team — a 'glue' Pokémon.