Mischa Barton straight-up denies crashing a U-Haul into an apartment building ... and we're guessing she'll deal with this fairly incriminating video once she gets to court.
TMZ broke the story ... the homeowners' association at The Park Wellington Condos in WeHo sued Mischa, alleging she misjudged the height of the carport before slamming into it and causing nearly $27k in damages. Mischa's now filed docs, obtained by TMZ, and she's denying it all.
It's a common move in civil cases to make a blanket denial, but we're guessing the video will be a tough thing to overcome. It shows Mischa clearly shaken right after the crash.
As we reported ... Park Wellington first tried to get Mischa's then-bf, Adam Spaw, to cover the damage, since he rented the truck. That insurance claim was denied, so now the HOA is going after Mischa, who is listed as the driver in the police report.
The crash came less than a month after Mischa's infamous meltdown.