Don’t look for Joan Rivers to be a guest on Jay Leno’s new talk show anytime soon.

The potty-mouthed comedienne ripped Leno and his upcoming 10PM series on NBC during a public press junket on Wednesday.

“I think it’s brilliant that Leno is at 10 p.m., because America can get bored more easily and go to sleep earlier,” Rivers told reporters as she promoted her new TV Land cable TV show How’d You You Get So Rich? at the Television Critics Assn Confab yesterday. “When was the last time you heard, ‘Did you hear what Leno said last night?’”

Rivers’ vendetta against the Tonight Show dates back more than two decades.

She was a frequent guest host for Johnny Carson — who banished her from the Tonight stage and refused to speak to her again after she began hosting her own late-night talk show on FOX in 1986.

The show was promptly cancelled.

Rivers was never asked back to Tonight again, even during Jay Leno’s 17-year run as host, which ended last May.