The 19-year-old was released by the Blues this summer after his contract expired.
The attacking midfielder has agreed a two-year deal with the Latics, with the option of a further year.
“Joe Royle at Everton pushed me towards Oldham because of his relationship with the club and I managed to get the move and I'm delighted to be here," he said.
“The gaffer has got a good footballing philosophy and he conducts himself very well so I can't wait to work under him.
“I play as a number 10 in the hole and I can bring creativity to the squad.
“I make chances for the strikers and want to pitch in with a few goals as well to help the club achieve promotion next season."