"We are delighted to sign him," Stoke's director of football John Rudge told the club's website.
"He is still a young, improving player who we feel has lots of potential. He is a big strong forward and we see him as an excellent acquisition."
The Mali international made 36 appearances for Gillingham last season - and Rudge revealed there is more to come.
"This is not the end because we are still looking to bring in another couple of forwards as well."

| Mamady Sidibe (Floating) Information | |||
| Date of birth | 18 December 1979 | Height | 6.4 |
| Place of birth | Bamako, Mali | Weight | 12.3 |
| Nationality | Position | Forward | |
| Comments | Squad No. | ||
Recent Career History By Club (1999 onwards) | ||||||
Team | Debut | Apps (+ sub) | Goals | Yellows | Reds | |
| 10/08/2002 | 87 (28) | 13 | 8 | 0 | ||
| 11/08/2001 | 29 (6) | 8 | 4 | 0 | ||
Recent Career History By Season (1999 onwards) | ||||||
Season | First App. | Apps (+ sub) | Goals | Yellows | Reds | |
| 07/08/2004 | 23 (13) | 3 | 1 | 0 | ||
| 09/08/2003 | 37 (8) | 6 | 4 | 0 | ||
| 10/08/2002 | 27 (7) | 4 | 3 | 0 | ||
| 11/08/2001 | 29 (6) | 8 | 4 | 0 | ||
Appearances 116 (+ 34 as sub); Goals 21; Yellow cards 12; Red cards 0 | ||||||