Fox began performing magic and comedy while working as a waiter in Saint Petersburg, Florida.
He learned sleight-of-hand in the 1970s from Tony Slydini, an Italian magician known as "the Master of Misdirection".
In his early twenties, Fox was performing in Boulder, Colorado, when he heard that his act had been stolen by a competing magician.
He was inspired to begin swallowing swords in order to have "an act people couldn't copy easily".
It took him eight months to master the technique, although he injured himself on several occasions learning it.
Fox estimated in 1999 he was one of only twenty professional sword swallowers in the United States, noting there were many more than when he began.

Fox could swallow up to 22 inches of steel.
Besides swallowing regular swords, his act included swallowing a retractable tape measure, a giant screwdriver and a neon glowing sword plugged into an outlet.
His act also included eating fire-until he learned that the chemicals used in the trick could seep into his liver.

Fox appeared at such venues as comedy clubs, casinos, and tattoo conventions, as well as special events such as an Aerosmith album release party.
His television appearances include the Late Show with David Letterman, a 1992 Jonathan Winters television special, and a Maalox commercial in which he swallowed light bulbs.
He was featured in the 2003 documentary Traveling Sideshow: Shocked and Amazed by Jeff Krulik.
 
Fox was the resident sword-swallower at the annual Maryland Renaissance Festival in Crownsville, and performed there from 1981 through 2017.
Prior to the festival's 2017 season, the festival's Royal Stage, where Fox performed, was renamed to the Royal Fox Theatre in his honor.
He began performing at the Sterling Renaissance Festival in Sterling, New York in 1997.
He occasionally worked as a consultant for other sideshow artists.
Fox began performing magic and comedy while working as a waiter in Saint Petersburg, Florida. He learned sleight-of-hand in the 1970s from Tony Slydini, an Italian magician known as "the Master of Misdirection". In his early twenties, Fox was performing in Boulder, Colorado, when he heard that his act had been stolen by a competing magician. He was inspired to begin swallowing swords in order to have "an act people couldn't copy easily". It took him eight months to master the technique, although he injured himself on several occasions learning it. Fox estimated in 1999 he was one of only twenty professional sword swallowers in the United States, noting there were many more than when he began.
Fox could swallow up to 22 inches of steel. Besides swallowing regular swords, his act included swallowing a retractable tape measure, a giant screwdriver and a neon glowing sword plugged into an outlet. His act also included eating fire-until he learned that the chemicals used in the trick could seep into his liver.
Fox appeared at such venues as comedy clubs, casinos, and tattoo conventions, as well as special events such as an Aerosmith album release party. His television appearances include the Late Show with David Letterman, a 1992 Jonathan Winters television special, and a Maalox commercial in which he swallowed light bulbs. He was featured in the 2003 documentary Traveling Sideshow: Shocked and Amazed by Jeff Krulik.  
Fox was the resident sword-swallower at the annual Maryland Renaissance Festival in Crownsville, and performed there from 1981 through 2017. Prior to the festival's 2017 season, the festival's Royal Stage, where Fox performed, was renamed to the Royal Fox Theatre in his honor. He began performing at the Sterling Renaissance Festival in Sterling, New York in 1997. He occasionally worked as a consultant for other sideshow artists.
Johnny Fox (performer)