| Mattias Sereinig | |
| Birth Date: | 17 November 1984 |
| Birth Place: | Klagenfurt, Austria |
| Position: | Midfielder |
| Currentclub: | Austria Klagenfurt |
| Clubnumber: | 33 |
| Years1: | 2003–2008 |
| Years2: | 2004 |
| Years3: | 2008–2009 |
| Years4: | 2009–2013 |
| Years5: | 2013–2015 |
| Years6: | 2015– |
| Clubs2: | BSV Juniors (loan) |
| Clubs4: | SCR Altach |
| Clubs5: | Wiener Neustadt |
| Clubs6: | Austria Klagenfurt |
| Caps1: | 94 |
| Caps2: | 2 |
| Caps3: | 8 |
| Caps4: | 117 |
| Caps5: | 48 |
| Caps6: | 25 |
| Goals1: | 1 |
| Goals2: | 0 |
| Goals3: | 0 |
| Goals4: | 3 |
| Goals5: | 1 |
| Goals6: | 0 |
| Pcupdate: | 31 May 2016 |
Mattias Sereinig (born 17 November 1984) is an Austrian football midfielder who plays for SC Wiener Neustadt. He previously played for SK Sturm Graz, SC Rheindorf Altach and SC Wiener Neustadt.[1]