The 28-year-old centre-back joins the French side following an agreement with Major League Soccer outfit Colorado Rapids. He has signed a long-term deal that will keep him at Nantes until June 2028.
Awaziem is no stranger to the club, having previously enjoyed a loan spell with Nantes during the 2017/18 season. He made 23 appearances and scored one goal in that campaign - an experience he remembers fondly, Panafricafootball.com wrote.
"When the opportunity came up, I didn't hesitate for a second to return - because for me, Nantes feels like home," Awaziem said.
"The people are amazing, the club is fantastic, and I've been eagerly awaiting the chance to come back. From a sporting perspective, I want to do everything I can to help the club achieve its goals, win trophies, and compete at the highest level. I want to bring Nantes back to the top."
Since his initial stint in France, Awaziem has built a career across Europe and North America, with spells in Turkey, Spain, Croatia, and Portugal, as well as in the United States with Colorado Rapids and FC Cincinnati.
On the international stage, the former FC Porto player has been a dependable figure for the Super Eagles since making his debut in 2017. He has earned 34 caps and represented Nigeria at the 2018 FIFA World Cup, along with three Africa Cup of Nations tournaments.
Awaziem's return adds valuable experience and leadership to the Nantes backline as they aim to improve on last season's Ligue 1 performance and compete for continental qualification.