Every M Mewtwo card we price, most valuable first. Prices are what copies actually sold for, updated daily.
The same Pokemon is also printed as Mewtwo, Team Rocket's Mewtwo, Mewtwo & Mew and Rocket's Mewtwo, priced separately because the game treats them as different cards.
What a M Mewtwo card is worth
The most valuable M Mewtwo on this list is M Mewtwo EX from Jumbo Cards at $150.95£113.61€132.94, and the 6 priced copies across 2 sets are worth $561£422€494 together. Most of that sits in a handful of printings: the older the set and the scarcer the print run, the wider the gap to the rest.
M Mewtwo is printed in Japanese as well: 2 cards across 2 sets, the most valuable of them M Mewtwo EX from The Best of XY at $37.91£28.53€33.39. Switch the list above to Japanese to read those, or to Both to rank the two catalogues against each other.
The highest PSA 10 on record for M Mewtwo sold for $2,750£2,070€2,422.
If you are trying to identify which M Mewtwo you have, the set name is printed on the card and the collector number sits in the bottom corner. Open the card here and the page carries every printing of it, the graded prices, and whether grading the copy is worth the fee. Sets to start with: Jumbo Cards, XY - BREAKthrough.