Using a tough guy image, he also starred in a series of famous TV commercials daring you to knock a battery off his shoulder.
But now, well into his senior years, Conrad loves his latest job- a radio talk show host. Once a week, Conrad takes his place in a Sunland studio at CRN digital talk radio.
The cable radio network is available in 11 million households all around the world.
"It's fun because I've had a career that's lasted 40 some years," said Conrad. "I directed, I wrote, I produced. Those were things I did in the part of my career that was recent. Now this radio is a way of saying to my audience, thank you. I can tell my audience thank you for the career that you gave me."
Conrad's career started in the ring after his mom took him to a gym in their tough Chicago neighborhood. Conrad said that his mother told one of the boxers that she wanted him to learn how to take care of himself.
"And I became a pretty successful boxer," said Conrad. "So that was part of what I did when I was younger."
Conrad's Hollywood career really took off when he starred opposite Connie Stevens in the TV series "Hawaiian Eye" from 1959 to 1963. And he learned to surf for the role.
Two years later he was back in the now classic western series, "The Wild Wild West." He did most of his own stunts on the show.
To this day, Conrad is matter-of-fact about the injuries he suffered beyond bumps and bruises.
"Six inch lineal fracture, high temporal concussion, broken skull," said Conrad on his radio show.
Conrad has never let injuries get in the way of work. In the 1970s he starred in "Baa Baa Black Sheep," also known as "Black Sheep Squadron." And he actually became a licensed pilot for the role.
Now, he's just enjoying his life on talk radio. So why should we listen?
"Because it's fun, it's an escape," said Cornad. "You're not going to hear the same old, same old."
Conrad's radio show airs every Thursday.