"Soliman penned the deal today afternoon," Ahli said in a statement on their official website.
"The player is very happy to have joined Ahli. Playing in the Saudi League will give him a great chance to show his abilities."
Soliman's last game with Petrojet will be against ENPPI in Monday's Egyptian Cup semi-final, after which he will begin his Ahli adventure.
The deal appeared on the verge of collapsing on Wednesday when Petrojet said they had backtracked on their decision to let the 25-year-old join Ahli.
But Soliman pleaded with the Egyptian league surprise package to accept Ahli's $500,000 offer and the club eventually granted him his wish.
Soliman has been in sparkling form this season, scoring five goals and providing numerous assists for his teammates.
His superb displays earned him a call-up to Egypt's squad.
Soliman will be the third Egyptian to play in the Saudi League. Emad Meteb joined Ittihad Jeddah in the summer while Tottenham's Hossam Ghaly recently moved to Nasr.