Do I need Prime Video to watch Spider-Noir?

Not necessarily.

Spider-Noir / Noir has been announced as an Amazon/MGM+ title, with U.S. distribution tied to MGM+ and broader/global distribution associated with Prime Video. So whether you need Prime Video depends on where you are and how you plan to watch it:

• In the U.S., you may need MGM+ rather than a standard Prime Video subscription. MGM+ can sometimes be bought separately or as a Prime Video Channel.
• Outside the U.S., it is expected to be on Prime Video in many regions, so a Prime Video subscription may be needed there.
• A regular Amazon Prime/Prime Video subscription may not include it if it is offered through an add-on like MGM+.

Short version: don’t subscribe to Prime Video just for Spider-Noir until the official watch page in your country confirms whether it’s included with Prime Video, requires MGM+, or needs another add-on. Exact release and platform details can change, so check Prime Video, MGM+, or the show’s official listing for your region.