The Mr Bean icon's girlfriend - 33-year-old actress Louise Ford - is apparently due to give birth in a matter of weeks, just in time for Christmas.
Ford had recently been spotted on a shopping trip in London looking heavily pregnant.
Louise is well-known for her roles in The Windsors and Crashing on Channel 4. HELLO! Online has reached out to Rowan's representatives for comment.
Atkinson has two adult children - 23-year-old Ben and 21-year-old Lily - from his previous marriage to former BBC make-up atrtist Sunetra Sastry.
Last month, Atkinson's daughter Lily, who works as a burlesque dancer, stopped using her father's surname and instead swapped to her mother's maiden name. An insider told Daily Mail at that time, "It's a real mystery".
"Atkinson has been Lily's name all her life but she's dropped it and is styling herself as Lily Sastry".
Hinting at a possible fallout with her father, the insider said, "I hope she hasn't fallen out with her dad. Not particularly challenging for someone with your abilities but it will massively entertain!"
His silent Mr Bean character - first seen in 1990 - has appeared in three hit movies so far.
While plenty of joy can come from having children at any age, most people find themselves thinking about becoming grandparents, rather than parents, once they've entered their 60s.