Hilary Duff -- Hot Bikini Selfie ... Divorce Does a Body Good

Here's Hilary Duff ... showing off what Mike Comrie will be missing out on now that she's decided to pull the plug on her marriage to the former hockey star.

Duff posted the pic to her Instagram account ... with the caption, "Hey #moms #westillgotit ❤️ #loveyourbod."

Duff and Comrie separated in January 2013 ... but she finally filed for divorce back in February.