The flag was designed by Councillors Peter Stock, Dewi Pritchard, Jim Brock and Marjorie Jacobs in the 1970s after the abolition of Pembrokeshire County Council.

A statement by Peter Stock, 'The flag was dedicated as the official flag of Pembrokeshire, at Pembroke Castle at a ceremony on 28 July 1988 with a march past by the band of The Queen's Dragoons Guards.'

[1] Joffre Swales, founder and conductor of the Haverfordwest Town Band, wrote a march entitled "The Pembrokeshire Flag" for the band to perform on marches around the county.

The blue is also considered to be reminiscent of the sea, and the yellow of summer sunshine.

The central rose represents the red Tudor Rose, a symbol used by King Henry VII, who founded the Tudor dynasty; a man of both Welsh and English descent who was born in Pembroke Castle.