"The Tonight Show" star said Stern, whose 1990s popularity peaked with a film and book release, is no longer a common household name since moving from public radio to satellite radio three years ago, The New York Times reported Sunday.
"On radio, Howard to me was a populist. The truck driver, the average guy would listen in the cafe, the truck, the old car that's 50 years old and still has an AM radio," Leno told the Times. "But I don't hear him quoted anymore. People don't say: 'Hey, did you hear what Howard said today?'"
Stern's employer, Sirius XM, is nearly $1 billion of debt as satellite radio has struggled to find a major consumer foothold.
Sirius Chief Executive Officer Mel Karmazin downplayed the declining value of the company's stocks, telling the Times the company must refinance to continue operations.
"I don't think that the performance of the stock is related to the performance of the company," he said. "It's related to the balance sheet of the company and the need for the company to refinance."