Every Porygon card we price, most valuable first. Prices are what copies actually sold for, updated daily.
What a Porygon card is worth
The most valuable Porygon on this list is Porygon (103a) from Aquapolis at $125£94.08€110.08, and the 23 priced copies across 21 sets are worth $489£368€431 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.
Porygon is printed in Japanese as well: 26 cards across 22 sets, the most valuable of them Porygon from Legends Promos at $53£39.89€46.68. 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 Porygon sold for $1,304£981.19€1,148. 1st Edition and reverse holo printings are priced separately from the standard card, because they do not trade at the same money.
If you are trying to identify which Porygon 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: Aquapolis, EX FireRed & LeafGreen, Base Set (Shadowless).