Arm River may refer to:

• Arm River (Saskatchewan), Saskatchewan
• Arm River (Tasmania), a tributary of Mersey River (Tasmania), Australia

• Rural Municipality of Arm River No. 252, a rural municipality in Saskatchewan
• Arm River (electoral district), a provincial electoral district in Saskatchewan
• Arm River-Watrous, a provincial electoral district in Saskatchewan
• Regina—Arm River, the former name of the federal electoral district Regina—Lumsden—Lake Centre, Saskatchewan

• Arm (disambiguation)