The Orb (French pronunciation: [ɔʁb]; Occitan: Òrb) is a 135.6-kilometre (84.3 mi) long river in the department of Hérault in the south of France. It flows into the Mediterranean Sea at Valras-Plage. The river flows through the towns of Bédarieux and Béziers, where it is crossed by the canal du Midi on the Orb Aqueduct.

The Orb flows through the following communes:

• Ceilhes-et-Rocozels
• Avène
• Le Bousquet-d'Orb
• La Tour-sur-Orb
• Bédarieux
• Hérépian
• Lamalou-les-Bains
• Le Poujol-sur-Orb
• Roquebrun
• Cessenon-sur-Orb
• Lignan-sur-Orb
• Béziers
• Sauvian
• Sérignan
• Valras-Plage

• 
  Orb river bridge at Cazouls
• 
  The Orb at Roquebrun
• 
  The Orb viewed from Béziers

The following rivers flow into the Orb:

• Jaur 30 kilometres (19 mi)
• Lirou 30 kilometres (19 mi)
• Mare 29 kilometres (18 mi)
• Taurou 25 kilometres (16 mi)
• Vernazobre 24 kilometres (15 mi)
• Rieutort 18 kilometres (11 mi)
• Héric 14 kilometres (9 mi)