The 33-year-old Blues keeper, the longest serving player on the clubs books, has signed for the Coca Cola Championship side on a free transfer.
Benno has been at St Andrew's for just over 12 years having joined the club from Peterborough for £325,000 in December 1993 but has fell down the pecking order in recent seasons and has recently had loan spells at both Sheffield United and Coventry.
During his time at St Andrew's, Benno, who's contract at Blues expired this summer, clocked up more than 300 appearances.
We wish him well during his time at his new club.