Year 9 BC was either a common year starting on Wednesday, Thursday or Friday or a leap year starting on Thursday of the Julian calendar and a leap year starting on Monday of the Proleptic Julian calendar. At the time, it was known as the Year of the Consulship of Drusus and Crispinus. The denomination 9 BC for this year has been used since the early medieval period, when the Anno Domini calendar era became the prevalent method in Europe for naming years.