A class submarine may refer to one of these classes of submarine:

• British A class submarine (1903), a class of 13 submarines of the Royal Navy that served in World War I
• Danish A class submarine, a class of six built for the Royal Danish Navy, 1911–1914
• Norwegian A class submarine, a class built for the Royal Norwegian Navy in 1913
• Soviet A class submarine, a later name for the American Holland or AG class submarines launched in 1916
• Spanish A class submarine, a class of three launched in 1917

• Plunger class submarine, a class of seven United States Navy submarines built before World War I; also known as the "A class"
• Amphion class submarine (also called the Archeron class), a class of sixteen submarines of the Royal Navy that served in World War II; also known as the "A class"

This article includes a list of ships with the same or similar names. If an internal link for a specific ship led you here, you may wish to change the link to point directly to the intended ship article, if one exists.