Margera was born in Concordville, Pennsylvania on July 13, 1957, where he was raised, as the second of seven children of Phillip and Darlene Margera (née Stauffer; October 13, 1939 - June 16, 2007). He moved to West Chester, where he met and married April Margera.
He first appeared on film in the CKY series of films, and it was these appearances that later got featured on Jackass. He was also in the main cast of Viva la Bam.
On television, Margera is depicted as kind, gentle, easygoing and quiet, whereas his brother Vincent "Don Vito" Margera is portrayed as loud and obnoxious. Margera has Italian ancestry and worked as a baker prior to his career in television.
Margera appeared on the second season of Celebrity Fit Club on VH1. When Celebrity Fit Club 2 began, he weighed in at 353 pounds (160 kg). He lost the most weight on the show, losing a total of 41 pounds (18 kg), down to 312 pounds (142 kg). In season 4, both BoneCrusher and Tina Yothers beat Margera's record, losing 51 and 42 lbs (23 and 19 kg) respectively. During a weigh-in on the show, Margera stated his reason for losing weight was to extend his life in order to spend more time with his granddaughter, Ava. He also appeared in the video game Tony Hawk's Underground 2, in which he joins Tony and Bam's crew on the World Destruction Tour wearing nothing but underwear and dress socks.