The two star right-handed pitchers will be honored at a ceremony May 3 before a game against Florida at Wrigley Field.
It will be the fifth number retired by the Cubs, joining No. 14 (Ernie Banks), No. 26 (Billy Williams), No. 10 (Ron Santo) and No. 23 (Ryne Sandberg).
Jenkins, elected to the Hall of Fame in 1991, and Maddux, who won 355 games before retiring in December, are the first pitchers in Cubs history to have their numbers retired.
Jenkins retired before the 1984 season. When Maddux broke in with the Cubs two years later, he was given No. 31.
"I remember walking down the stairs there at the clubhouse. I got called up in September from Des Moines and it was just right there in my locker," Maddux said of the No. 31. "Being 20 years old at the time the last thing I was going to do was complain about my number. I was just happy to be there."
A few weeks later Maddux learned he had been given the same number that Jenkins wore with the Cubs.
"I thought that was pretty cool. They gave me Fergie's number. I knew he was one of the best pitchers to ever play for the Cubs and for baseball period."
Turns out Maddux became one of the greatest, too.
"Both of us had I think brilliant careers," Jenkins said. "He won a Cy Young as a Cub and I did it, also. I think it was a productive number."
Maddux said he didn't give much thought to having his number retired during his first stint with Chicago from 1986-1992 but acknowledged he did during his second stretch.
"I thought it was pretty cool. I always liked seeing Ryno's number up there because I had played with him," Maddux said.
Jenkins went 167-132 with a 3.20 ERA in 401 appearances during two stints with the Cubs. He was a three-time NL All-Star (1967, 1971 and 1972) and won the 1971 NL. Cy Young Award after going 24-13. During his 19-year career that also included stops with the Phillies, Rangers and Red Sox, he had a 284-226 record with a 3.34 ERA. He pitched 267 complete games.
Maddux won 133 games for the Cubs and earned the first of four consecutive NL Cy Young Awards with the Cubs in 1992, when he went 20-11 with a 2.18 ERA. He then signed with Atlanta.