"Yeah, I mean, I think in any business where there's activity that is just flat out wrong, somebody's got to go, and it starts from the top," Lemonis said on CNBC's "Power Lunch" on Friday.
Wells Fargo has been accused of creating roughly 2 million phantom accounts without customers' knowledge, in order to meet company sales targets, as the Wall Street Journal first reported.
The bank has agreed to pay $185 million in penalties and $5 million to customers and has separately fired 5,300 people over the scandal. The House Committee will call Stumpf to testify as part of the investigation.
"If something like that happened in my own business, I would expect to be held accountable for it," said Lemonis, who is the CEO of Camping World.
Lemonis, who helps struggling businesses on CNBC's "The Profit," explained what he would do if he was in Stumpf's position.
"My first move would have been to find out exactly what happened and to really come back with a transparent analysis," he said. "I would probably acknowledge if I knew there was a sales organization doing these things, of course you'd have to resign."
"I don't know if there's been enough swiftness in determining how did it happen," Lemonis said. "It wasn't like five accounts were open."