A plasma torpedo was a weapon consisting of a torpedo armed with a charge of plasma, most often used as a starship mounted weapon.

The Romulan Empire developed their own version of the weapon and by the mid 23rd century had created extremely powerful plasma torpedoes that could envelop and destroy a target, even targets made of hard materials like cast rodinium. However the weapons had limited range and would dissipate after a few minutes of high warp travel.