Jarry replaces injured Columbus Blue Jackets goalie Joonas Korpisalo, and Letang, a defenseman, replaces Penguins forward Jake Guentzel on the Metropolitan Division team.
Jarry would play in his first NHL All-Star Game. The 24-year-old is 14-6-1 with a 2.04 goals-against average, .934 save percentage and three shutouts.
"It surprised me," Jarry said. "It's exciting. It's something every kid dreams of. You watch it every year, and you think it's something that would be cool to be a part of. It's something I'll take in stride."
Letang would play in his sixth All-Star Game, surpassing Paul Coffey for the most by a Pittsburgh defenseman. The 32-year-old has 28 points (10 goals, 18 assists) in 35 games this season.
"It's fun to be named sometimes, but I think there are guys more deserving than me on that team," Letang said.
Korpisalo is out after having knee surgery Dec. 30. Guentzel is out after having shoulder surgery Dec. 31.
The All-Star Game will be played Jan. 25 in St. Louis.
"We're obviously thrilled for the two of them," Penguins coach Mike Sullivan said. "They're both deserving through their body of work in the first half of the season. They've both played extremely well, and it will be a great thrill for both of them."
NHL.com correspondent Danny Webster contributed to this report
