A 1906 letter by the Bailiff of Jersey, describing the flag as "the red St Andrew's cross on white ground", states it was used to signal the neutrality of the Channel Islands during wars between England and France.

The St Patrick's Cross is commonly identified with the arms of the FitzGeralds, a Cambro-Norman family which became powerful in Ireland, and who also owned land in Jersey.

[6] The use of the red saltire became more common during the German Occupation of World War II, as the local population were not allowed to display the Union Flag in occupied territory.

Although the heraldic symbols of Jersey were used by the Island's government during this time, all public buildings and landmarks (such as Fort Regent and Mont Orgueil) flew the Flag of Nazi Germany.

[10] The flag, which is the British Red Ensign with the badge and crown in the fly, was approved by Queen Elizabeth II,[11] and subsequently by the States of Jersey in June 2010.

[12] A government Blue Ensign, with the badge without the crown in the fly, was given a general warrant in 1997, having originally been issued in 1907 specifically for the government-owned tugboat Duke of Normandy.