The 25-year-old only joined the Spireites last December from National League North side Chester on an 18-month contract for a fee believed to be around £25,000 with add-ons.
He made 17 appearances for the Blues in what was a stop-start season for the left-sided player.
He has signed a two-year deal with the Magpies.
His departure follows the arrival of Calvin Miller last month, who plays in the same position, who was on loan at Notts last season from Harrogate.
As well as Miller, the Spireites also have Alex Whittle in that position.
Notts County head coach, Ian Burchnall, said: “We needed a wing back who could offer a threat one-against-one.
"Joel’s pace in the wide areas and his ability to attack in those moments is really important.
“He’s been playing wing back at Chesterfield and, based on the games we’ve seen, he was most effective when they were attacking. With us being a team that wants to do that, we feel he’ll suit us well.
“With Joel we have to look at the whole package, including his age and potential. He’s got the capacity to develop his game further and we feel we can help him do that in this environment.”
Chesterfield manager James Rowe warned of more ‘upheaval’ before the start of the season in an interview with the DT and said people would need to ‘trust’ his decision-making.
"The club would like to thank Joel for his services and wish him all the best for the future,” Chesterfield said in a statement.