Earlier this year, the Romanian manufacturer announced plans to compete in the Dakar in 2025 following what labelled as a "test phase" during 2024, when it will enter selected events of the FIA World Rally-Raid Championship.
Al-Attiyah, who has won the Dakar in 2011, 2015, 2019, 2022 and 2023, will join World Rally legend Loeb and Spanish driver Cristina Gutierrez in Dacia's official line-up.
The Qatari will have to wait until 2025 to compete with Dacia in the Dakar, as he will drive a Prodrive-built Hunter T1+ in 2024.
Along with his usual co-driver, Matthieu Baumel, the five-time winner of the rally will be testing the car in order to develop it and arrive better prepared for the next edition of the event.
Dacia's yet-to-be-unveiled prototype will run on synthetic fuel, as already revealed in its presentation in July.
Despite Dacia's lack of experience in the Dakar, Al-Attiyah said the goal was to win in its maiden outing.
"I'm really happy to be part of the Dacia," said Al-Attiyah. "I think it will be a really good team and strong, and we'll try to win from the first year."
He added: "It's a dream team. I have a lot of respect for Sebastien Loeb and Cristina and I have a good relationship with both drivers. We are really very strong and our aim is to win with this beautiful brand Dacia."
The 46th edition of the Dakar will start on 5 January, with a route entirely in Saudi Arabia.
The event will cover 7,891 kilometres, of which 4,727 kilometres will be timed.
The rally will also feature a new 48-hour challenge with a 584km timed marathon that will start in the morning, stop in the evening and resume the following day.