No, Jeff Dunham (born Jeffrey Dunham on April 18, 1962 in Dallas, Texas) has never appeared on the TV series America's Got Talent.
The man you are most likely thinking of is Terry Fator (born Terry Wayne Fator on June 10, 1965 in Dallas, Texas). He was the singing ventriloquist that won the America's Got Talent show in 2007 and credits Jeff Dunham as "a huge inspiration to me."
Jeff Dunham is a global entertainment phenomenon with more than 45 years on stage and countless performances, making him one the world’s most recognizable and inventive entertainers.
Want to become a good ventriloquist? Check out these tips and how to instructions shared by Comedyventriloquist.com.