Ford will be engine partners from next season with Red Bull, Ricciardo's former team in Formula 1 and with which he took seven of his eight wins.
The 36-year-old last raced in 2024 for the Red Bull-owned team that is now Racing Bulls.
"While my racing days are behind me, my love for anything with wheels will always remain high and for that I am proud to be partnering with Ford to become a Global Ford Racing Ambassador," he wrote in a blog post for Ford Racing.
"When I decided it was time to retire, I thought long and hard about finding the most authentic way to stay connected to the world of motorsports.
"For me, racing was always about having fun. It made me happy and created memories that will last a lifetime."
The announcement coincided with the Italian Grand Prix at Monza, a race Ricciardo won for McLaren in 2021.