Ahhhhhhh, public domain. When a previously copyrighted movie loses its copyright (or it never had one to begin with) and that movie becomes perfectly legal to watch for free. To be honest – a lot of public domain flicks are pretty damn terrible, but if you are willing to sift through a lot of crap – you can find some diamonds on the rough.
So here, I’d like to highlight some of the best public domain horror moives out there that you can watch right now and not pay a penny for. From overlooked low budget gems to famous horror pictures that hold a great deal of respect with horror fans. Each and every one of these films are completely free… FREE!
1) Alice, Sweet Alice
Twelve year old Alice lives with her mother and younger sister Karen. During Karen’s fist communion she is brutally murdered by a masked assailant.

This film was also known as Communion and Holy Terror. Due to changes in distributors and various other legal problems, the film was never properly registered for copyright. You can watch Alice, Sweet Alice right here.
2) Satan’s School for Girls
A young woman investigating her sister’s suicide at a private girls’ school finds herself battling a satanic cult.

Produced by Aaron Spelling – yes, THAT Aaron Spelling. This made for TV movie was long forgotten about and nobody bothered to secure a copyright for it. You can watch Stan’s School for Girls right here.
3) Rehearsal for Murder
A year after his fiancée’s death, a playwright schedules a rehearsal for his new play, which proves to be a trap for her killer.

Yet another made for TV movie that nobody bothered to copyright. This one has a few recognisable names like; Robert Preston, Lynn Redgrave, Patrick Macnee and Jeff Goldblum. You can watch Rehearsal for Murder right here.
4) House on Haunted Hill
Eccentric millionaire Fredrick Loren and his wife, Annabelle, have invited five people to the house on Haunted Hill for a ‘haunted house’ party. Whoever can stay in the house for one night will earn ten thousand dollars each.

From director William Castle. The original copyright holder failed to renew the film’s copyright resulting in it falling into the public domain. You can watch House on Haunted Hill right here.
5) Carnival of Souls
After a traumatic accident, a woman becomes drawn to a mysterious abandoned carnival.

When originally released – the film was a failure in the box office so the producers distanced themselves from the movie and didn’t bother to renew its copyright. Yet today its regarded as a landmark in psychological horror. You can watch Carnival of Souls right here.
6) Night of the Living Dead
A group of characters barricade themselves in an old farmhouse in an attempt to remain safe from flesh eating zombies.

One of the most infamous and influential horror films ever made. Director George A. Romero created the modern zombie with this one… just a shame he forgot to apply a copyright to the film. You can watch Night of the Living Dead right here.
7) Tormented
A man lets a former flame fall to her death rather than let her interfere with his new relationship, but her ghost returns to disrupt his impending nuptials.

A little campy and dated but don’t let that introduction music put you off because there is an effective and creepy ghost story here. Yet another film where the copyright was never renewed. You can watch Tormented right here.
There are plenty more public domain horror films out there to discover – some great, some not so great. I have merely scratched the surface with this list, but there are hundreds more to find and watch.