| Birth Date: | 1983 9, df=yes |
| Birth Place: | Neuwied, West Germany |
| Position: | Left-Winger |
| Youthclubs1: | TuS Mayen |
| Youthyears2: | –2002 |
| Youthclubs2: | 1. FC Kaiserslautern |
| Youthyears3: | 2002–2003 |
| Youthclubs3: | TuS Mayen |
| Years1: | 2003–2006 |
| Clubs1: | Eintracht Trier |
| Caps1: | 48 |
| Goals1: | 8 |
| Years2: | 2006–2007 |
| Clubs2: | 1. FC Kaiserslautern II |
| Caps2: | 28 |
| Goals2: | 0 |
| Years3: | 2007–2009 |
| Clubs3: | Kickers Emden |
| Caps3: | 36 |
| Goals3: | 3 |
| Years4: | 2009–2010 |
| Clubs4: | SV Elversberg 07 |
| Caps4: | 20 |
| Goals4: | 2 |
| Years5: | 2010–2013 |
| Clubs5: | TuS Koblenz |
| Caps5: | 78 |
| Goals5: | 13 |
| Years6: | 2013–2017 |
| Clubs6: | FC Karbach |
| Caps6: | 56 |
| Goals6: | 22 |
| Manageryears1: | 2016–2017 |
| Managerclubs1: | FC Karbach (player-assistant) |
| Manageryears2: | 2018 |
| Managerclubs2: | Fola Esch |
Thomas Klasen (born 16 September 1983) is a retired German footballer and current football coach, most recently in charge of CS Fola Esch.[1] [2]