The former "Parks and Recreation" star gave birth this summer, a source has told Us Weekly magazine.
Jones, who was previously engaged to music producer Mark Ronson and dated John Krasinski, Colin Jost and Jon Favreau, was first romantically linked to the singer in 2016, but neither has confirmed the relationship rumours.
Don't expect the reported baby to prompt Rashida, who is the daughter of legendary producer Quincy Jones, to get married - she's made it clear she has no plans to tie the knot.
"Marriage doesn't really buy you anything," she previously said. "Chris Messina, who is my co-star in 'Monogamy', is with my very close friend (producer Jennifer Todd) and they're not married, but they have two kids and they're wildly happy."
"It (marriage) just buys you a really big s**tty pageant of a wedding to make other people happy. Things are changing so much. Especially (in) this country (America), (where) we have kind of failed with marriage. We're so protective of this really sacred but failed institution. There's got to be a new model."
And the actress, 42, admitted she was tired of friends and relatives putting marriage pressure on her: "It's just this weird thing that's been hammered into my head culturally: that's the only way to succeed, that's the only thing that counts for a woman.
"I'm happy, but the fact that I'm not married and don't have kids - it's taken me a long time to get to a place where I actually am OK with that, where I actually don't feel like I'm some sort of loser."