Paris was heading into Fia Restaurant Monday night in Santa Monica with her sister, Nicky -- who was hosting the French Sole summer dinner party -- when a photog asked about Britney's battle.

Clearly, nothing's changed for Paris -- she's still very much on board with the "Free Britney" movement. You'll recall she publicly declared her position during her DJ set in Las Vegas ... days after Brit's testimony.

But, Paris' support for Britney dates back to last year when she told Andy Cohen, "I just love her so much. I feel like if you are an adult, you should be able to live your life and not be controlled."

As we've reported ... Britney posted #FreeBritney herself last week after crying in court and reiterating her desire to end the conservatorship. She also made claims that her father, Jamie, and others had threatened her, and said she wants her dad investigated for conservator abuse.