Lindsay Lohan -- I Didn't Fight ANYONE!!!

Lindsay Lohan is adamant -- she didn't fight with anyone inside a nightclub last Thursday night -- because sources close to LiLo tell TMZ ... she wasn't even out that night.

As TMZ first reported, a woman filed an incident report alleging battery with the West Hollywood Sheriff's Department, claiming Lindsay started a fight with her inside a nightclub last week.

According to our sources, Lindsay claims she didn't even leave the house that night. We're told Lindsay stayed home and watched TV that night -- she's currently catching up on the Showtime series "Homeland."

Our sources say Lindsay is particularly frustrated by this accusation ... because even when she stays home and avoids trouble, she feels it seems to find her anyway.