The 21-year-old has penned a one-year deal with the option to extend his stay by a further 12 months.
Ball was released by Derby at the end of last season following a five-year stay with the Rams.
St Mirren start the new Scottish Premiership season with a trip to Motherwell on August 9.
Restore Data
| Team | P | W | D | L | F | A | GD | PTS | |
| 1 | Celtic | 11 | 10 | 1 | 0 | 31 | 3 | 28 | 31 |
| 2 | Aberdeen | 11 | 10 | 1 | 0 | 24 | 10 | 14 | 31 |
| 3 | RangersRangers | 11 | 7 | 1 | 3 | 16 | 8 | 8 | 22 |
| 4 | Dundee UnitedDundee Utd | 12 | 5 | 4 | 3 | 18 | 13 | 5 | 19 |
| 5 | Motherwell | 11 | 6 | 1 | 4 | 15 | 14 | 1 | 19 |
| 6 | St Mirren | 13 | 4 | 3 | 6 | 17 | 22 | -5 | 15 |
| 7 | Dundee | 12 | 3 | 3 | 6 | 18 | 24 | -6 | 12 |
| 8 | Kilmarnock | 12 | 3 | 3 | 6 | 15 | 25 | -10 | 12 |
| 9 | Ross County | 13 | 2 | 6 | 5 | 10 | 21 | -11 | 12 |
| 10 | St Johnstone | 13 | 3 | 1 | 9 | 16 | 27 | -11 | 10 |
| 11 | Hearts | 13 | 2 | 3 | 8 | 14 | 20 | -6 | 9 |
| 12 | Hibernian | 12 | 1 | 5 | 6 | 11 | 18 | -7 | 8 |
| > Scottish Premiership Full Table | |||||||||
