Fakhar Zaman will represent Glamorgan for the first half of T20 Blast, the club announced on Monday.
Zaman will feature for Glamorgan in eight games, replacing Shaun Marsh who suffered from a broken arm during a practice session in the World Cup.
"It is disappointing to lose Shaun Marsh for the start of the competition but to secure the services of Fakhar on short notice is great news for the club," Glamorgan's Director of Cricket Mark Wallace said.
"He is a fantastic cricketer and one of the most destructive batsmen in the world who has a history of performing in big matches."
Fakhar had an ordinary run in the World Cup, scoring just one half-century at the top of the order as Pakistan had failed to qualify for the semi-finals.
However, the opening batsman said he was excited on getting the opportunity.
"I'm thrilled to sign for Glamorgan and look forward to playing in Cardiff," said Fakhar.
"I have fond memories of the ground from our Champions Trophy semi-final here in 2017 and look forward to making some new ones. Glamorgan is a fantastic club and hopefully, I can put in some match-winning performances for the team during my stay."