Bro or BRO may refer to:

• Bro, Sweden, a place in Upplands-Bro Municipality, Stockholm County
• Bro (Gotland) on Gotland island
• Kristinehamn, formerly a town called Bro or Broo

The hypobromite ion, also called alkaline bromine water, is BrO^-. Bromine is in the +1 oxidation state. Hypobromite is the bromine compound analogous to hypochlorites found in common bleaches, and in immune cells. In many ways, hypobromite functions in the same manner as hypochlorite, and is also used as a germicide and antiparasitic in both industrial applications, and in the immune system.