R406 road may refer to:

• R406 road (Ireland)
• R406 road (South Africa)

• British coin Three Halfpence
• British coin Triple Unite
• British coin Two Guineas
• British coin Two Pounds (pre-decimal)
• British Collegiate American Football League
• British Collegiate American Football League (BCAFL)
• British colloquium for theoretical computer science
• British Colloquium for Theoretical Computer Science
• British Colombia
• British Colonial
• British colonial empire
• British colonialism
• British Colonial Office
• British colonial rule
• British Colonial Taxpayers and All Workers Union
• British Colonies
• British colonies in North America
• British colonies of North America
• British colonization of Africa
• British Colony
• British Colony and Protectorate of Nigeria
• British columbia
• British Columbia Amateur Hockey Association
• British Columbia Ambulance Service
• British Columbia Assessment