"Jersey Shore" star Deena Cortese was arrested for disorderly conduct this afternoon in Seaside Heights, NJ ... law enforcement sources tell TMZ.

In a video obtained by TMZ, Deena can be seen dancing through the streets. The cops seem to be tolerating her behavior for a few minutes, but after awhile they decide they've had enough.

You can see Deena cuffed, put in the back of a cop car and driven away ... while Ronnie and Sammi look on.

It's been a busy weekend for the cast -- as TMZ previously reported, the fellas from the show were in a bar brawl that appeared to leave Jwoww with a sprained ankle.