The 50-year-old Oscar victor, who has two children already, was spotted on the red carpet at the Butterfly Ball in Los Angeles with her hands over her stomach as if cradling her "bump". "She is not pregnant", her reps told Page Six.
She's also the mum to daughter Nahla, aged nine, who she shares with Gabriel Aubry from their previous relationship.
Social media users reacted with prematurely congratulatory messages.
Folks were mostly ecstatic at the idea of Halle Berry and Janet Jackson both spearheading the club of celebrity women giving birth at 50.
'I mean, I didn't think it was possible to have another baby ... We haven't even mentioned her home life since 2015 when news broke that she and then-husband Olivier Martinez were divorcing, and her first and second husbands, David Justice and Eric Benet, respectively, tried to warn him.
We're not usually ones for hysterically announcing that any female celeb who's more likely just enjoyed a particularly carb-heavy lunch must be sporting a baby bump.