The flag is a banner of the arms of Hertfordshire County Council.

On 19 November 2008 the Council passed a resolution that the design is a fitting and proper emblem for the county and its people.

[3] The blue and white wavy lines, a traditional heraldic representation of a water course, symbolise the county's many rivers while the shield and hart are taken from the arms of the Borough of Hertford.

[4] It is a heraldic pun of Hart and ford.

The Hart reclines on a yellow field, representing Saint Alban, the patron saint of Hertfordshire and first British martyr, whose cross is traditionally yellow on blue.