The XXXG-01H Gundam Heavyarms (aka Heavyarms or Gundam Zero-Three) is a mobile suit from the TV anime Mobile Suit Gundam Wing. It was the third of Operation Meteor's five Gundams, and was piloted by a young man operating under the pseudonym Trowa Barton.

Created by Gundam Scientist Doktor S, the Heavyarms was developed in the L3 Colonies under the financial support of the Barton Foundation. The Heavyarms is a long-range attack unit with a variety of built-in firearms. Its design is a combination of the firepower aspect of the Wing Gundam Zero with an emphasis on overwhelming suppressive fire. Its overall firepower is comparable to 3 to 5 battleships', but its attack power drops drastically once it run out of ammunition. However, with the skilled circus performer Trowa's excellent piloting sense, the Heavyarms is capable of acrobatic melee combat.