Ms Maniapoto says intellectual property laws will be a concern under the TPPA.
"I found that out when I could not sing under my name in Germany. Ford, Sony and the US have exclusive rights over Maori icons and other taonga that were guaranteed in our treaty."
IOF spokesman Edward Miller said there was an unprecedented groundswell of public concern over the TPPA.
The rallies follow a campaign in late 2013 that opposed the secrecy of the TPPA, where 26,000 signatures or letters called for release of the draft text.
Last month, the Labour, Greens, NZ First, Mana and Maori parties made similar demands. The national day of action is being co-ordinated by It's Our Future, and is supported by the Green, New Zealand First, Maori and Mana parties.
The TPPA is a mega-deal that has been under secret negotiation for four years, aside from leaked texts.
The 12 countries involved are New Zealand, the United States, Australia, Brunei, Canada, Chile, Malaysia, Mexico, Peru, Singapore and Vietnam.
IOF say enough is known to show that it could impact on a broad range of life, from Pharmac and the internet, give foreign investors the right to sue the Government over tighter mining laws or tobacco control, prevent Buy Kiwi rules for local and central government, stop the establishment of new SOEs, such as Labour's proposed KiwiAssure, and more.
Locals are invited to meet at the Silver Ball sculpture on the riverfront and walk to Majestic Square at 1pm on Saturday to meet for the nationwide rally.