Ash was designed by Atsuko Nishida, and named after creator Satoshi Tajiri. The character was designed to represent how Tajiri was as a child, obsessed with catching bugs.

The young boy’s name is Ash Ketchum. Or, at least, it is in English-language versions. In the original Japanese, his name was Satoshi, after the creator of Pokémon, Satoshi Tajiri. He based Ash /Satoshi on his childhood self; his early fascination with catching bugs inspired the premise of Pokémon.

When they were changing the show so it was easier for North Americans to understand, the character's name was changed in the anime to "Ash Ketchum", the first name taken from one of the possible names players could choose for the character in the games, and the last name tying into 4Kids early catchphrase for the series, "Gotta catch 'em all!"

His last name Ketchum is a pun of the Original Motto of the series "Gotta Catch 'em All!" His first name Ash, may come from the series creator S a to sh i.