The Santisima Trinidad (officially named Nuestra Señora de la Santísima Trinidad) was a Spanish first-rate ship of the line. At launch in 1769, she had 112 guns, though this number gradually increased. between 1795 and 1796 she was upgraded to 130 guns, and in 1802 this number was increased to 140. Following this last rebuild, she was the heaviest armed ship in the world, bearing more guns than any other ship in the Age of Sail. Effectively, however, the fourth gundecks guns were comparatively small.
This armament was not without its problems. The weight of the additional weaponry rendered her a particularly poor at sail, leading to the ultimately rejected suggestion that she be restricted to the defence of the Bay of Cadiz. She remains notable as one of the very few 4-decked ships ever built.