HMS Alliance (P417/S67) is a Royal Navy A-class, Amphion-class or Acheron-class submarine, laid down towards the end of the Second World War and completed in 1947.

The Amphion-class submarines were designed for use in the Far East, where the size of the Pacific Ocean made long-range, high surface speed and relative comfort for the crew important features to allow for much larger patrol areas and longer periods at sea than British submarines operating in the Atlantic or Mediterranean had to contend with.

From 9 October 1947 until 8 November the submarine undertook a lengthy experimental cruise in the Atlantic Ocean off the coast of Africa to investigate the limits of the snort mast, remaining submerged for 30 days.

In August 1979, she was towed to Vosper Ship Repairers Limited's yard at Southampton to have her keel strengthened so that she could be lifted out of the water and preserved as a memorial to those British submariners who have died in service.

Although listed as part of the National Historic Fleet, in recent years as many as 100 pigeons had been nesting in the submarine, causing extensive corrosive damage.