The blonde DJ flew into Las Vegas from Aspen, Colorado, where she had been enjoying a post-Christmas skiing break with her loved ones.
Paris will ring in the New Year at the Hyde Bellagio but first on her Vegas agenda was showing her support for Britney by joining sister Nicky Hilton to watch Britney: Piece Of Me at the Planet Hollywood Resort and Casino.
Britney will perform 50 shows over a two-year period and lucky Paris was one of the first to see the pop princess's hit-packed extravaganza.
And clearly Britney was happy to see her old friend, tweeting: "@ParisHilton @NickyHilton Lovely seeing you both in the audience tonight! Miss you girls!!"
Paris and Britney were firm friends a few years ago, frequently seen out and about together at the hottest clubs in LA but, just because they haven't been snapped together in a while, that doesn't mean that friendship has fizzled out.
Back in September, Paris told MTV News: "I love Britney. I've loved her. I think she's so beautiful. I love her music and I'm so proud of her." Paris also gave the thumbs up to Brit's hit single 'Work Bxxxh'.
Paris will celebrate the New Year in typically glamorous style this evening when she DJs at the Hyde Bellagio.
"So excited for my party tomorrow night at @HydeBellagio!" she tweeted yesterday. "It's going to be an incredible night! See you there!"