Stossel's regular "Give Me a Break" segments prodded at groupthink, and he wrote best-selling books under that name and "Myths, Lies and Downright Stupidity." Yet activists have called for his firing, and the network compelled him to apologize for a 2000 report questioning the safety of organic produce.
A year later, Stossel had to film new interviews after parents objected to their children being interviewed for a show on what they were taught about the environment. Stossel said the parents were "brainwashed" by his environmental critics.
"I'm grateful to ABC for allowing me to do stories that challenged conventional wisdom, and occasionally enraged many of its viewers," Stossel said in a blog posting. "But it's been said that everyone should change jobs every seven years. I've been at ABC for 28 years."
He said he wanted to explore the concepts of liberty and limited government. "Fox offers me more airtime and a new challenge," he said.
Stossel had complained on his blog earlier this summer when a story he did on Canadian health care was temporarily shelved for Michael Jackson coverage on the week of the pop star's death. The story ran later.
Stossel also carved out a specialty in family issues. Two of his ABC specials, "Teens: What Makes Them Tick" and "Love, Lust and Marriage" finished in Nielsen Media Research's top 10 in the weeks they were aired in the late 1990s.
Roger Ailes, Fox News chairman and CEO, said Stossel "has done meaningful and important work throughout his career. His thoughtful and charismatic style has carved a unique niche in the world of television."
Before he became an anchor on "20/20," Stossel was a consumer reporter on ABC's "Good Morning America" and on CBS' New York affiliate.
Stossel follows other former ABC journalists Brit Hume and Chris Wallace in moving to Fox.
ABC said in a statement that "we will miss him."