Admiral of the Fleet Sir Algernon McLennan Lyons (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.
Lyons also served as Commander-in-Chief, Pacific Station, Commander-in-Chief, North America and West Indies Station and then Commander-in-Chief, Plymouth.
He was the nephew of the eminent Admiral Edmund Lyons, 1st Baron Lyons, who served as Commander-in-Chief of the Mediterranean Fleet, under whom he served for a time, and the cousin of Richard Lyons, 1st Viscount Lyons and Richard Lyons Pearson, Assistant Commissioner of the Metropolitan Police.