Slater, 47, holds the record for being both the youngest and oldest World Championin the men's ranks.
He won his first world title in 1992 at the age of 20 and his last was in 2011.
The Piha Pro will be the first time Slater has competed in New Zealand since 1993.
The Piha Pro is one stop on the newly-announced WSL Challenger Series which will see more than 100 surfers chasing qualifying for the elite Championship Tour in 2021.
"This is a real coup for the Piha Pro. To have the greatest of all time in our first year goes to show how well-regarded Piha is as a surf destination. It gives us a real stamp of credibility and is going to create hype around the sporting community in New Zealand," said event director Chris Simpson.
Slater said he was looking forward to returning to New Zealand.
"I'm excited to be surfing again in an event in New Zealand and seeing all my fans there. I love the country and all it has to offer... incredible surf, golf and so much more.
The competition will run from March 16th-22nd.