Michael Gross is padding the staff of Avenue with two high-profile contributing editors.

Anthony Haden-Guest, the well-known British journalist and raconteur about town, will ­contribute a weekly cartoon to the Avenue.com website and a monthly one to the magazine.

Although more famous for his columns and books such as “The Last Party: Studio 54, Disco, and the Culture of the Night” and “True Colors: The Real Life of the Art World,” he has also been a noteworthy — if less-publicized — cartoonist, with two books of cartoons and verse to his credit.

Nina Griscom, the former Ford model well known in society circles, will pen a dishy last page of the magazine beginning ­in January.

She’s the stepdaughter of legendary investment banker Felix Rohatyn and spouse of real estate agent Leonel Piraino. The couple’s Central Park duplex has been featured in Architectural Digest.