The 20-year-old Londoner spent last season with Blackburn Rovers in the Championship, making 23 appearances in all competitions and scoring once.
He cut his teeth at Arsenal, leaving the Gunners in 2024 to sign for Brighton, and was immediately sent out to Ewood Park to gain more experience.
Left footed, Cozier-Duberry has played a lot of football on the right side of the attack but can play centrally and down the left.
On signing for the club on loan, Amario Cozier-Duberry said: “I'm feeling good and I'm really happy to be here.
"There wasn't much of a decision for me to make because once I had spoken to Fergal and Steven, my mind was made up. The conversations were good and they spoke about how much they believe in me and had faith in me, and I want to show that on the pitch.
"The club has big ambitions, and I'm proud to be part of such a big club. I can't wait to get in, interact with the lads and get going."
Head Coach Steven Schumacher said: “Amario is another exciting signing for us and we are thrilled to welcome him to the Football Club.
“He arrives with huge amounts of potential and the staff and I are really looking forward to working with him and helping him to develop and grow as both a person and a player.
“Having tracked him closely for a while, we know he is someone who loves to attack and have the ball at his feet - and like Thierry - offers us a profile of player that we have been looking for throughout this summer.
"With his previous experiences, especially playing in the Championship last season, we know he has the ability to succeed in a Bolton shirt. With our pre-season trip just around the corner, Amario arrives at the perfect time to easily bed into the playing group ahead of the upcoming campaign.”