The flag of Derbyshire is the flag of the English county of Derbyshire. Introduced unofficially in 2006, the flag has subsequently been registered at the Flag Institute and added to their UK Flags Register.
The flag features a green cross on a blue background. These colours were chosen to represent Derbyshire's green countryside and its rivers and reservoirs, respectively. In the centre of the flag is a Tudor rose, which has been the county badge since the 1470s. The rose is gold in colour rather than the more usual red and white, partly to differentiate from the emblems of Yorkshire and Lancashire; it is also supposed to symbolise quality.