Chappell, 25, came through at Leicestershire and was in high demand when he moved to Trent Bridge at the end of 2018. But he only managed 18 appearances for Notts across all three formats in four seasons with the club, twice going out on loan to Gloucestershire.
He featured in Nottinghamshire’s Royal London Cup opener on Tuesday and will remain available for selection until the end of the summer.
“Zak is an incredibly skilled bowler and a great addition to our attack for all formats,” Derbyshire’s head of cricket, Mickey Arthur, said. “He probably hasn’t played the amount of cricket he’s wanted to in recent years, but he’s kept developing and worked hard on his game, now he has the chance to show what he can do as part of our bowling unit.
“Signing Zak is a big move for the club, as it gives us even more competition and quality within our ranks for the 2023 season and beyond.”
Chappell claimed his best first-class bowling figures of 6 for 44 with Leicestershire in 2018, but has not played consistently since then. He has taken nine Championship wickets at 37.77 this season, but enjoyed more success in the Blast with 11 wickets and an economy of 7.70.
Chappell said: “When I heard of Derbyshire’s interest, I jumped at the chance to come and work with a top-class coaching unit in Mickey Arthur and Ajmal Shahzad.
“Last season, I played a good amount across all formats and I feel I’m at a point now where I need to be playing top-level cricket week in, week out and signing for Derbyshire gives me the chance to do that.
“Derbyshire have an ambitious project with plenty of quality in the squad. You can see the direction Mickey wants to take the club in and that really attracted me.”
Nottinghamshire’s head coach Peter Moores said that injuries and competition for places had limited Chappell’s chances at Trent Bridge.
“Our bowling attack has certainly been competitive to break into for this past couple of years and that, combined with picking up some injuries at key times, has limited Zak’s opportunities to play first-team cricket,” Moores said. “He wants to be playing regularly across all formats. Hopefully this move gives him an opportunity to do that, and it keeps him close to his roots in the East Midlands, so we completely understand and respect his decision.
“His attitude around the group has been positive throughout his time at Trent Bridge. He trains hard, has gone about his periods of injury rehab professionally and has handled his decision to leave in a respectful and positive way.
“There’s lots to play for and plenty we can still achieve during the remainder of the season – and I know Zak will be giving it everything. Once we get to the end of September, it will be a case of thanking him for his efforts and wishing him well for the next part of his career.”