NBC Universal is trying to improve its financial performance under the ownership of Comcast Corp., which bought the entertainment company last year.
Leno had been making between $25 million to $30 million annually as the host of "The Tonight Show." His salary will be reduced to about $20 million after making the job-saving concessions. Leno also brings in substantial income touring as a stand-up comedian.
"Jay's foremost concern is for the wonderful people who work with him at 'The Tonight Show,'" said Bruce Bobbins, a spokesman for Leno. "He did what was necessary to ensure their well-being."
Several other staffers on "The Tonight Show" also absorbed pay cuts.
David Letterman, the host of a rival late-night show on CBS, accepted a significant pay cut in 2009.
The show's cost-cutting measures were first reported by Deadline Hollywood, a website that tracks the entertainment industry.
Comcast bought a controlling interest in NBC Universal for $6.2 billion in cash and several cable-TV channels valued at $7.25 billion. Besides its TV network and several cable channels, NBC also owns the Universal Pictures movie studio and theme parks.
Comcast, which is based in Philadelphia, makes most of its money selling cable TV and high-speed Internet access.
Despite its solid ratings, "The Tonight Show" hasn't been a big moneymaker. That prompted the cuts Friday, which are expected to trim the program's weekly budget by about $600,000, or 25 percent, to $1.7 million. That's back to its levels of a few years ago.
Leno outmaneuvered Letterman to succeed Johnny Carson as "The Tonight Show" host in 1992 and remained in one of television's most sought-after jobs for the next 17 years. At NBC's behest, he left the show in 2009 and was replaced by Conan O'Brien. After a few months hosting his own show in an earlier time slot, Leno returned as "The Tonight Show" host in 2010 in a decision that provoked a nasty fight between O'Brien and NBC.
O'Brien now hosts a late-night talk show on TBS
During Leno's brief stint hosting his prime-time program, his show's weekly budget escalated and wasn't reduced significantly to reflect his return to the late-night slot until now.