The 22-year-old Ali has played 35 white-ball matches for his country, including two appearances at the recent ICC T20 World Cup, where Pakistan were runners-up to England. In 33 T20I appearances, he has scored 499 runs, including three half-centuries, one of which came against England at Emirates Old Trafford in 2020.
Announcing Ali's signing on Friday, Derbyshire recognised his red-ball abilities also, citing an average of 54.33 from 11 first-class appearances, including three centuries and four half-centuries. He will be available in all formats during the 2023 county season, subject to international commitments, and joins Sri Lankan fast bowler Suranga Lakmal as the club's overseas signings.
"I spoke with him at the T20 World Cup, and again during the Lanka Premier League, and he's so hungry to come to England and prove himself in all formats, that's exactly the attitude we want in our dressing room. Of course, he still has a lot of developing to do, but I've outlined what I expect from him and I have no doubt Haider will succeed in county cricket."
Ali said: "I've seen over the last few years how many Pakistan players have improved their game by playing at a high standard in county cricket, and that's something I think could really help my development.
"Mickey Arthur is such a respected figure in world cricket and he's still so highly regarded within the Pakistan set-up, so the opportunity to learn from him is one I'm so excited about... there's a lot of good players here and Mickey wants to achieve something big with this club. Hopefully I can contribute a lot of runs in 2023 and entertain the Derbyshire crowd."