How can I watch a theatrical release of the original trilogy online

Doctor_c said:

How can I watch a theatrical release of the original trilogy online?

In answer to your question… you don’t.

If any online platform did this, and it became popular, it’d likely soon receive a ‘cease and desist’ order - or simply shut down.
 

There are occasionally dodgy ‘apps’ or TV/IPTV ‘services’ that may feature the unaltered theatrical cuts of the Original Trilogy as mentioned in here - The Unaltered Trilogy on Roku - as well as ‘veetle’-like online services that may screen the theatrical cuts… yet they are few and far between (and don’t seem to last long before being shut down or disappearing; IPTV being an exception).
 

If you’d like to acquire a copy of the unaltered theatrical cuts of the Original Trilogy head over to the Star Wars Preservation section of the site - and give the pinned ❕ An Index Of Projects & Help Thread for Star Wars Preservations… ❕ a read through… to see which Star Wars preservation projects appeal to you (usually, the Harmy Despecialized Editions or the 4K77/80/83 projects are among the more popular and highly rated endeavours around).

^ Obviously, you must be in ownership of the official retail release to acquire any such project here - as per the Fan Project Rules.

Please also give the following useful ‘info and help threads’ a read through to help you learn how to acquire such projects…

❕ Welcome to the OriginalTrilogy.com | Introduce yourself in here | Useful info within ❕ | About | Help | Announcements

❕ ‘How Do I Do This?’ on the OriginalTrilogy.com; some info & answers + member FAQs ❕ | Site Rules | Fan Project Rules

‘I have found a Fan Edit / Preservation I am interested in - but I don’t know how to get / acquire it?’ - in General Assistance

‘Please leave some feedback for the fan projects on here - or even a review…’ (and join in with the discussions on this forum!) 😃
 

Good luck with it. 👍