"The land we're negotiating is the land we once shed blood over.
"Now, through the Treaty Settlement process, we are choosing to work together for the return of land for the mutual benefit of both Ngāti Rangitihi and Tūhourangi."
TTA Chairman Alan Skipwith said the signing marked an important chapter in the relationship between the two iwi.
"For us, it represents recognition between our two iwi, of the strong whakapapa hononga and our shared whenua interests at Tarawera," Skipwith said.
He said he hoped that return of the lands would allow future generations to reconnect with their tribal lands.
Both Iwi have a long-standing emotional connection with the area once world famous for the Pink and White Terraces.
"These feelings only strengthen the resolve of Ngāti Rangitihi and Tūhourangi to work together to regain ownership of these culturally significant lands."
In 2017, Ngāti Rangitihi and Tūhourangi jointly purchased Waimangu Volcanic Valley Limited, an eco-tourism experience south of Rotorua.
Skipwith said the signing of the Deed between the two Iwi showed an enduring commitment to work together.
"We have shown through our partnership at Waimangu Volcanic Valley that we are good stewards of our whenua, and we are looking forward to being able to extend this to those areas that are of cultural significance to us," he said.