The 31-year-old was released by the Baggies last month following a four-year spell at The Hawthorns.
He is now expected to sign a deal at Selhurst Park as Palace prepare for life in the Premier League, according to the Daily Mail.
Thomas, who started his career with Arsenal, arrived at West Brom from Portsmouth in 2009.
Restore Data
| Team | P | W | D | L | F | A | GD | PTS | |
| 1 | Leeds UnitedLeeds | 21 | 12 | 6 | 3 | 37 | 15 | 22 | 42 |
| 2 | Sheffield UnitedSheff Utd | 20 | 13 | 5 | 2 | 28 | 11 | 17 | 42 |
| 3 | Burnley | 20 | 10 | 8 | 2 | 24 | 7 | 17 | 38 |
| 4 | Sunderland | 20 | 10 | 7 | 3 | 29 | 15 | 14 | 37 |
| 5 | Blackburn RoversBlackburn | 19 | 10 | 4 | 5 | 23 | 17 | 6 | 34 |
| 6 | West Bromwich AlbionWest Brom | 20 | 7 | 11 | 2 | 23 | 14 | 9 | 32 |
| 7 | Middlesbrough | 20 | 9 | 4 | 7 | 34 | 25 | 9 | 31 |
| 8 | Watford | 19 | 9 | 4 | 6 | 27 | 25 | 2 | 31 |
| 9 | Swansea CitySwansea | 20 | 7 | 6 | 7 | 21 | 19 | 2 | 27 |
| 10 | Bristol City | 21 | 6 | 9 | 6 | 26 | 26 | 0 | 27 |
| 11 | Norwich CityNorwich | 20 | 6 | 8 | 6 | 35 | 30 | 5 | 26 |
| 12 | Sheffield WednesdaySheff Weds | 20 | 7 | 5 | 8 | 23 | 29 | -6 | 26 |
| 13 | Millwall | 19 | 6 | 7 | 6 | 20 | 17 | 3 | 25 |
| 14 | Derby CountyDerby | 21 | 6 | 6 | 9 | 26 | 26 | 0 | 24 |
| 15 | Coventry CityCoventry | 21 | 6 | 6 | 9 | 27 | 30 | -3 | 24 |
| 16 | Preston North EndPreston | 21 | 4 | 11 | 6 | 21 | 27 | -6 | 23 |
| 17 | Queens Park RangersQPR | 21 | 4 | 10 | 7 | 21 | 27 | -6 | 22 |
| 18 | Luton TownLuton | 20 | 6 | 4 | 10 | 23 | 35 | -12 | 22 |
| 19 | Stoke CityStoke | 20 | 5 | 6 | 9 | 21 | 26 | -5 | 21 |
| 20 | Oxford UnitedOxford Utd | 19 | 4 | 6 | 9 | 20 | 30 | -10 | 18 |
| 21 | Portsmouth | 19 | 3 | 8 | 8 | 21 | 34 | -13 | 17 |
| 22 | Cardiff CityCardiff | 19 | 4 | 5 | 10 | 17 | 30 | -13 | 17 |
| 23 | Plymouth ArgylePlymouth | 19 | 4 | 5 | 10 | 19 | 40 | -21 | 17 |
| 24 | Hull City | 21 | 3 | 7 | 11 | 19 | 30 | -11 | 16 |
| > Championship Full Table | |||||||||
