Kim Kardashian Vs Old Navy

Kim is filing a lawsuit against the clothing giant -- claiming they intentionally used a look-alike in an effort to dupe the public into thinking Kim was affiliated with Old Navy.

We're told Kim is especially furious that Old Navy has been tweeting to her page about the look-alike -- in an effort to gain even more publicity.

One of those tweets read, "@CBSNEWS reports that Old Navy's Super CUTE star looks like @kimkardashian. #LOL. What do you think?"