A character published by Marvel Comics. Thunderbolt Ross first appeared in The Incredible Hulk #1 in 1962.

Thaddeus E. Ross was born into a family with a long history of military service. Ross followed in the family tradition, graduating from West Point with honors and serving in the Pacific theater during World War II with the Air Force. During that time, Ross rose in rank and acquired the nickname Thunderbolt from his troops, who said that he struck like a thunderbolt. During the Korean War, Ross rose to the rank of general.

After his return to the States, Ross was given command of a nuclear testing facility in the American southwest. Ross's wife gave birth to their only child, a daughter named Betty. Mrs. Ross died soon after and Ross was left to raise their daughter on his own. Feeling that the base was not a good place for her to grow up, Ross sent Betty to a boarding school.

Ross chafed under the inactivity of commanding the base, preferring the excitement of battle. He also was annoyed that command of the chief project of the base, the construction and testing of a gamma bomb, was given to a civilian, Bruce Banner. Banner was bookish and unathletic earning Banner Ross's dislike and lack of respect. Ross also found further reason to dislike Banner when Ross's daughter Betty returned from boarding school and began a budding romance with the quiet doctor.

Ross's life changed dramatically on the day of the testing of the gamma bomb. A breach of the testing site by a local teenager, Rick Jones and the subsequent attempt by Banner to save the boy resulted in Banner being exposed to the radiation of the exploding gamma bomb. Banner's exposure produced the effect of causing him to turn into a massive brutish figure of immense strength and destructive power called by Betty Ross, the Hulk. Ross was given the job of trying to capture or kill this new menace, though he was unaware of the fact that his lead scientist and the creature he sought were one in the same. Ross did notice that Banner began to disappear and suspected that he was working for communist agents.

During this time, Ross brought a young officer named Glen Talbot to the base to work as head of security. Ross hoped the Talbot would attract Betty's attention away from Banner and in some ways, he did. When Banner and the Hulk were believed killed, Banner's friend Rick Jones revealed to Talbot and Betty that Banner was also the Hulk, resulting that when they returned alive, Banner was forced to become a fugitive, running from Ross, Talbot, and their group of soldiers known as the Hulkbusters.

For years, Ross and Talbot attempted to capture or kill the Hulk, but although they would succeed for a time in capturing the beast, he would always break free. Finally the strain of hunting the Hulk paid its toll on the two with Talbot being killed in battle with the Hulk and Ross having a mental breakdown. Ross eventually recovered and made a deal with the villain the Abomination to kill the Hulk. Ross later admitted his duplicity and was given a dishonorable discharge from the military.

Banner later was apparently cured of being the Hulk and was to be married to Betty Ross. Thunderbolt Ross turned up at the wedding armed with a pistol and tried to stop the wedding. Ross shot Rick Jones, who attempted to disarm him, and Betty talked her father into giving up and returning to a mental institution.

The former general was approached by members of S.H.I.E.L.D. who asked him to participate in an experiment with the energy being known as Zzzax. Why S.H.I.E.L.D. chose an insane ex-military man with an obsession for the Hulk as their experiment subject was never fully explained, but the result of the experiment was that it left Ross's body on life support and his mind inside the electrical creature. With the power of Zzzax at his bidding, Ross escaped from S.H.I.E.L.D. and attempted to do what he had been unable to do for years: kill the Hulk. Ross/Zzzax was defeated when he realized that he had been wrong about Banner and the Hulk, when Banner nearly sacrificed his life to save Betty's from a life-force sucking monster. Ross instead sacrificed himself to defeat the monster and save his daughter.

The character of Thunderbolt Ross will appear in the 2003 Ang Lee movie The Hulk. He will be portrayed by actor Sam Elliott.