Admiral of the Blue was a senior rank of the Royal Navy of the United Kingdom, immediately outranked by the rank Admiral of the White (see order of precedence below).

In 1688 the formal flag rank of Admiral of the Fleet was created.

[3] The Admiral of the Blue was a senior rank of the Royal Navy of the United Kingdom, immediately outranked by the rank Admiral of the White (see order of precedence below).

[4] The Navy was divided into three squadrons White, Blue and Red, in order of seniority.

Ships of the Royal Navy flew the Ensign that coincided with the squadron of their commanding officer.