Storm went to California to visit his sister, Susan, who had moved there hoping to become an actress and there become engaged to marry aeronautical engineer Reed Richards. Richards was working on a starship of his own design that would make possible travel to other solar systems through hyperspace. When the United States government threatened to cut off its partial funding for the project, Richards decided to make an immediate test flight. He himself would ride in the starship, with his friend Benjamin Grimm acting as pilot. Susan and Johnny Storm insisted on going along as well. Sneaking onto the launch site and into the starship, the four launched themselves into space. The starship encountered unexpected intense radiation, which proved to be too much for the ship's shielding to block out. (It has been theorized that this was the result of a reduction in the extent of Earth's magnetosphere brought on by a solar flare.) As a result, the four people in the ship were exposed to intense cosmic ray bombardment. Aborting the test flight, the four returned to Earth.
Upon landing, Johnny Storm discovered that the cosmic rays had mutagenically altered his entire body, enabling him to create fiery plasma all about his body without harm to himself. Storm called himself the Human Torch, the same name used by the android hero of the 1940's. Storm agreed to join Richards' proposed team of champions, the Fantastic Four.
For a time Johnny Storm tried to live quietly on Long Island with his sister, trying to finish high school while hoping that no one in the community would realize that he was the Human Torch, a fact that proved impossible to conceal from the townspeople. After graduation, Johnny moved into the Fantastic Four's Baxter Building headquarters in New York City.
After many years, Johnny began dating and then married the blind sculptress Alicia Masters, former girlfriend of teammate the Thing, who was then on a sabbatical from the team. This caused some tension between him and the Thing when he returned to the team, and later Storm suspected the Thing of inviting Crystal to join the Fantastic Four to test his marital fidelity as a way of seeking revenge or splitting his wife. Crystal soon left the team, however, and the Thing began a relationship with their other associate, the second Ms. Marvel.
Later, Alicia Masters was revealed to be a spy from the alien race of shape-changing Skrulls. Lyja, the Skrull, had fallen in love with Storm and married him. The revelation of Lyja led the team to infiltrate the Skrull homeworld to rescue the real Alicia, who was still in love with the Thing, and the Skrulls captured Lyja. Although Lyja managed to escape, her relationship with Storm was damaged, turning Storm from a hotheaded brash adult to a solemn and brooding one. Lyja returned to Earth to attempt a reconciliation and reveal that she was pregnant, a fact which began to turn Storm around, although he never fully recovered his love for what he thought was Alicia. Lyja's "child" ended up being a Skrull bio-weapon, which the Four quickly defeated. Eventually, Storm began to date again, and has since moved on in romantic terms.
Afterwards, Storm was involved alongside the Four and other heroes against the menace known as Onslaught. Although he appeared to sacrifice himself to stop the creature, he was actually shunted to another dimension and later restored to this reality.
More recently, Storm encountered the heroine Namorita, and the two had a brief but well-publicized romance. He has also tried his hand at becoming a movie star.