Hilary Duff — Bikini Ready … 3 Months After Baby

Jessica Simpson should probably take note … “cause Hilary Duff has already bounced back to bikini form … just 3 months after giving birth.

The 24-year-old actress — who”s married to retired hockey star Mike Comrie — was hangin” by a pool in Mexico … relaxing with her new son Luca Cruz, who was just born on March 20.

It appears Duff has already dropped most of the baby weight … and she doesn”t even have a $4 million deal with a weight loss company.

Nice work.