The 30-year-old Frenchman has penned a four-year deal at the Camp Nou with the option to extend it by a further 12 months.
The Catalan club has also announced that the full-back has a buyout clause of £39.5m.
Mathieu, who joined Valencia from Toulouse in 2009, scored four goals in 42 appearances last season.
Restore Data
| Team | P | W | D | L | F | A | GD | PTS | |
| 1 | Barcelona | 8 | 7 | 0 | 1 | 25 | 9 | 16 | 21 |
| 2 | Real Madrid | 8 | 5 | 3 | 0 | 17 | 6 | 11 | 18 |
| 3 | Villarreal | 8 | 5 | 2 | 1 | 17 | 15 | 2 | 17 |
| 4 | Atletico MadridAtletico | 8 | 4 | 4 | 0 | 12 | 4 | 8 | 16 |
| 5 | Osasuna | 9 | 4 | 3 | 2 | 13 | 14 | -1 | 15 |
| 6 | Athletic Bilbao | 8 | 4 | 2 | 2 | 12 | 8 | 4 | 14 |
| 7 | Mallorca | 9 | 4 | 2 | 3 | 9 | 8 | 1 | 14 |
| 8 | Rayo Vallecano | 9 | 3 | 4 | 2 | 11 | 9 | 2 | 13 |
| 9 | Celta Vigo | 9 | 4 | 1 | 4 | 16 | 15 | 1 | 13 |
| 10 | Real BetisBetis | 8 | 3 | 3 | 2 | 8 | 7 | 1 | 12 |
| 11 | AlavesAlaves | 8 | 3 | 1 | 4 | 11 | 12 | -1 | 10 |
| 12 | Espanyol | 9 | 3 | 1 | 5 | 9 | 13 | -4 | 10 |
| 13 | GironaGirona | 8 | 2 | 3 | 3 | 9 | 11 | -2 | 9 |
| 14 | Sevilla | 8 | 2 | 3 | 3 | 8 | 10 | -2 | 9 |
| 15 | Real Sociedad | 8 | 2 | 2 | 4 | 6 | 7 | -1 | 8 |
| 16 | Getafe | 9 | 1 | 5 | 3 | 6 | 7 | -1 | 8 |
| 17 | Leganes | 9 | 1 | 5 | 3 | 5 | 9 | -4 | 8 |
| 18 | Valencia | 9 | 1 | 3 | 5 | 5 | 13 | -8 | 6 |
| 19 | Real ValladolidValladolid | 9 | 1 | 2 | 6 | 5 | 19 | -14 | 5 |
| 20 | Las PalmasLas Palmas | 9 | 0 | 3 | 6 | 9 | 17 | -8 | 3 |
| > La Liga Full Table | |||||||||
