| Mateusz Siebert | |
| Fullname: | Mateusz Filip Siebert |
| Birth Date: | 4 April 1989 |
| Birth Place: | Poznań, Poland |
| Position: | Centre-back |
| Youthclubs1: | Metz |
| Years1: | 2008–2010 |
| Clubs1: | Metz |
| Caps1: | 1 |
| Goals1: | 0 |
| Years2: | 2009–2010 |
| Clubs2: | → Arka Gdynia (loan) |
| Caps2: | 17 |
| Goals2: | 0 |
| Years3: | 2010 |
| Clubs3: | Metz B |
| Caps3: | 9 |
| Goals3: | 1 |
| Years4: | 2011–2012 |
| Clubs4: | Arka Gdynia |
| Caps4: | 11 |
| Goals4: | 0 |
| Years5: | 2013–2022 |
| Clubs5: | US Rumelange |
| Caps5: | 143 |
| Goals5: | 1 |
| Totalcaps: | 181 |
| Totalgoals: | 2 |
| Nationalyears1: | 2008 |
| Nationalteam1: | Poland U19 |
| Nationalcaps1: | 1 |
| Nationalgoals1: | 0 |
| Nationalyears3: | 2009–2010 |
| Nationalteam3: | Poland U21 |
| Nationalcaps3: | 6 |
| Nationalgoals3: | 0 |
Mateusz Filip Siebert (born 4 April 1989) is a Polish former professional footballer who played as a centre-back.
Born in Poland, he moved to France with his family at the age of three. His father Bernard is a former professional Polish footballer and his mother Renata a former handball player.[1] He acquired French nationality on 3 November 1998, through the collective effect of his father's naturalization.[2]
He made his Ligue 2 debut in October 2008, coming on as a 25th-minute substitute against LB Châteauroux. In July 2009 he joined Arka Gdynia on a one-year loan with a buy option.[3] His season ended in March as a result of injury. Despite wishing to retain him, the small club did not take up the buy option due to cost.[4]
In February 2011, he joined Arka Gdynia on a two-and-a-half-year contract.[5]
Siebert was a part of the Poland U-21 team.[6]