GANDALF himself – aka Sir Ian McKellen – will introduce one of the first public showings of “The Lord of the Rings.”

The sold-out performance is at midnight Tuesday at the Lincoln Square IMAX theater.

A number of other theaters have scheduled midnight showings, including the E-Walk, the Kips Bay, the Chelsea West, the Cinema I and the E. 86th St. Cinemas.

Regular engagements begin Wednesday morning for the $100 million, three-hour adaptation of J.R.R. Tolkien’s fantasy.