Riyad Mahrez has won the Premier League five times - once with Leicester and four times with Manchester City
The 32-year-old, who had two years left on his contract, is the latest big-name recruit by the SPL in a deal worth up to £30m.
City paid £60m for Algeria winger Mahrez in 2018, and he scored 15 goals in 47 games in the Blues' Treble-winning campaign last season.
"To play for Manchester City has been an honour and privilege," said Mahrez.
"I came to City to win trophies and enjoy my football. I achieved all that and so much more.
"I've made a lifetime of wonderful memories. Manchester City will forever be a huge and happy part of my life."
Mahrez helped City win 10 major honours during five seasons with the club but was an unused substitute for both the FA Cup and Champions League finals.
City's director of football, Txiki Begiristain, said: "Riyad has been a major factor in our amazing successes over the past five years and his contribution will not be forgotten.
"He is a wonderful footballer to watch and leaves us with so many great memories.
"There are few wingers that possess his levels of skill and technique in world football, and he will be missed, but everyone will wish him all the best as he begins a new chapter in his career."
The likes of Karim Benzema, N'Golo Kante and Ruben Neves have already followed Cristiano Ronaldo to Saudi Arabia this summer, while Steven Gerrard has been named Al-Ettifaq manager and Michael Emenalo has been appointed the SPL's director of football.
Former Liverpool captain Jordan Henderson completed a transfer to Gerrard's Al-Ettifaq on Thursday.
The country's Public Investment Fund (PIF) has also taken over four of the SPL's leading clubs, including Al-Ahli, as the league aims to become one of the top five in the world.
Mahrez was the only senior player to miss City's pre-season tour of Asia.
The futures of England defender Kyle Walker, Portugal midfielder Bernardo Silva and Spain defender Aymeric Laporte have all been the subject of speculation this summer, but all three have travelled.
Reports in Germany have suggested Bayern Munich have agreed a deal for Walker, but it is thought they are wide of the mark.
Portugal full-back Joao Cancelo is also part of the City squad after Bayern chose not to take up the option of turning last season's six-month loan into a permanent deal.
It is understood goalkeeper Zach Steffen is absent with a knee injury, although City are open to the idea of the USA international moving on this summer.
-- Courtesy of BBC Sport