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 | 26 | 15 | 8 | 3 | 48 | 19 | 29 | 53 |
| 2 | Burnley | 26 | 14 | 10 | 2 | 31 | 9 | 22 | 52 |
| 3 | Sheffield UnitedSheff Utd | 26 | 16 | 6 | 4 | 36 | 17 | 19 | 52 |
| 4 | Sunderland | 26 | 14 | 8 | 4 | 39 | 22 | 17 | 50 |
| 5 | Blackburn RoversBlackburn | 26 | 12 | 6 | 8 | 31 | 23 | 8 | 42 |
| 6 | Middlesbrough | 26 | 11 | 8 | 7 | 43 | 32 | 11 | 41 |
| 7 | West Bromwich AlbionWest Brom | 26 | 9 | 13 | 4 | 32 | 21 | 11 | 40 |
| 8 | Watford | 26 | 11 | 5 | 10 | 36 | 37 | -1 | 38 |
| 9 | Bristol City | 26 | 9 | 10 | 7 | 33 | 30 | 3 | 37 |
| 10 | Sheffield WednesdaySheff Weds | 26 | 10 | 7 | 9 | 38 | 40 | -2 | 37 |
| 11 | Norwich CityNorwich | 26 | 9 | 9 | 8 | 43 | 37 | 6 | 36 |
| 12 | Swansea CitySwansea | 26 | 9 | 7 | 10 | 30 | 30 | 0 | 34 |
| 13 | Queens Park RangersQPR | 26 | 7 | 11 | 8 | 29 | 34 | -5 | 32 |
| 14 | Millwall | 25 | 7 | 9 | 9 | 24 | 23 | 1 | 30 |
| 15 | Preston North EndPreston | 26 | 6 | 12 | 8 | 28 | 34 | -6 | 30 |
| 16 | Coventry CityCoventry | 26 | 7 | 8 | 11 | 34 | 37 | -3 | 29 |
| 17 | Oxford UnitedOxford Utd | 26 | 7 | 8 | 11 | 29 | 41 | -12 | 29 |
| 18 | Derby CountyDerby | 26 | 7 | 6 | 13 | 31 | 35 | -4 | 27 |
| 19 | Stoke CityStoke | 26 | 6 | 9 | 11 | 24 | 32 | -8 | 27 |
| 20 | Luton TownLuton | 26 | 7 | 4 | 15 | 27 | 44 | -17 | 25 |
| 21 | Cardiff CityCardiff | 26 | 5 | 9 | 12 | 26 | 41 | -15 | 24 |
| 22 | Hull City | 26 | 5 | 8 | 13 | 25 | 36 | -11 | 23 |
| 23 | Portsmouth | 25 | 5 | 8 | 12 | 30 | 44 | -14 | 23 |
| 24 | Plymouth ArgylePlymouth | 26 | 4 | 9 | 13 | 25 | 54 | -29 | 21 |
| > Championship Full Table | |||||||||
