What county are Sleepy Hollow and Tarrytown NY in? By Henry John Steiner On January 20, 2020 Sleepy Hollow and Tarrytown are in Westchester County, NY. Please follow and like us: Related Previous Is there a library in Tarrytown NY? Next How did Sleepy Hollow get its name? Comment on this FAQ Cancel replyYour email address will not be published. Required fields are marked *Comment Name * Email * Website Save my name, email, and website in this browser for the next time I comment. Notify me of new posts by email.