Netflix will participate in the Internet-Wide Day of Action, according to organiser Fight for the Future.
The event is due to take place on 12th July to protest FCC chairman Ajit Pai's proposal to roll back Title II classification of ISPs and rethink the rules against blocking, throttling and paid prioritisation.
Amazon, Reddit, Mozilla, Etsy and Vimeo are among those already signed on.
"Politicians in Washington, DC need to learn that net neutrality is not a partisan issue and internet users will not tolerate these attacks on our basic rights - we will come together to protect the web as an open platform for free expression and exchange of ideas," said Fight for the Future campaign director Evan Greer.
Fight for the Future says that 12th July will be a "day of action" on net neutrality, similar to the previous internet slowdown and SOPA blackout, part of the successful campaign to stop the Stop Online Piracy Act, not the first time that similarity has been invoked in the present pushback on FCC chair Ajit Pai.
Rather than a slowdown, Fight for the Future suggests it will be a speed up of actions to fight against the Title II rollback, saying the effort will focus on grassroots mobilisation including public interest groups energising their members and web platforms providing tools for the public to contact politicians and the FCC.