Admiral of the Fleet Sir Algernon McLennan Lyons GCB ADC DL JP (30 August 1833 – 9 February 1908) was a senior Royal Navy officer who served as First and Principal Naval Aide-de-Camp to Queen Victoria.

[4][3][2] Lyons was promoted to mate in October 1853 and transferred to the paddle frigate HMS Firebrand, which was engaged in the blockade of the Danube Delta, which was being held by the Russians at the start of the Crimean War.

[2][3] During the blockade of the mouth of the Danube, Captain Parker, Lyons's commanding officer, decided to attack the guardhouses and signal stations higher up the River, for these were responsible for the supply and communication of the Russian enemy.

When he reached the first Russian fort, defended by a stockade and a battery, Captain Parker was shot and killed by a Cossack.

When the British flagship, HMS Albion, was set on fire by the Russians, Lyons attached it, whilst burning, to his own ship and towed it to safety.

[6][3][2] Lyons became commanding officer of the sloop HMS Racer on the North America and West Indies Station in May 1860.

[5] In HMS Racer he had the difficult task of protecting British merchant vessels seeking to evade the blockade being imposed by the United States Navy on Confederate ports.

He became a Knight Grand Cross of the Order of the Bath in June 1897[11] and was promoted Admiral of the Fleet on 23 August 1897.