Matthieu Serge Fernand Saunier (born 7 February 1990) is a French professional footballer who plays for FC Lorient as a central defender.
Saunier previously played for Bordeaux, where he began his professional career. Immediately after signing his professional contract, Saunier was loaned to Championnat National club Rodez. After a season there, for the second consecutive season, he was loaned out, this time to Troyes. After a successful campaign in which he became the "leader of the defense", the move was made permanent in June 2011.
On 4 August 2016, Saunier signed for La Liga club Granada CF.
Saunier is a French youth international, having represented his nation at under-17 and under-20 level. In 2007, he was a part of the under-17 team that played at both the 2007 UEFA European Under-17 Football Championship and 2007 FIFA U-17 World Cup.