We've spotted a hot new fall trend! Inside of a week, we've seen Kim Kardashian, Nicky Hilton AND Alessandra Ambrosio sporting red pants in LA!

While Kim wore hers high-waisted (she Tweeted that she's been into menswear lately), Nicky and Alessandra worked the capri look!

And these hotties prove you can dress the look up or down -- Kim is ready to head out for the night, Nicky's on her way to a meeting and Alessandra is enjoying a day with her fam at the pumpkin patch!

If you can believe it, we ALSO saw two more celeb hotties out in ruby bottoms -- AnnaLynne McCord and JoJo! They put their own spin on the look; see how the gals sported scarlet pants after the jump!