Barnes (5-0-KO1), who has two Olympic bronze medals to his name, will enjoy home support in Belfast as he bids to conquer the world in just his sixth bout as a professional.
Nicaragua’s Rosales (27-3-KO18) has been outpointed by Kal Yafai and Andrew Selby in the past but won the WBC crown with a stunning ninth-round stoppage of Daigo Higa back in April.
Barnes said: “I’m extremely excited. I’ve been boxing for 20 years and I made history by becoming a two-time Olympic medallist. Now I can become a world champion early in my pro career and make more history.
“My last fight was back in November but I’ve been in training camp since January as the original plan was to fight in March. It’s been frustrating but I always have faith in MTK Global and they’ve delivered.
“As for Rosales, he’s on a knockout streak so I know he can punch but he’s also a very good boxer. I think our styles will gel perfectly and the fans are in for a real war.
“He’s only lost three times to high-class opponents like Kal Yafai and Andrew Selby. Yafai outmuscled him and Selby outboxed him. I’m hoping I can do a bit of both.
“The atmosphere on the night will be absolutely incredible. Belfast as a city is full of knowledgeable boxing fans and they’ll get behind me against a very good world champion.
“I’ve fought all around the world in massive arenas and I loved it every time. This one will be extra special as it’s in my home city. I won’t be fazed by it – it will inspire me.”
A red letter night of boxing includes WBO interim world featherweight champion Carl Frampton – also from Belfast – clashing with the unbeaten Luke Jackson, with lineal world heavyweight king Tyson Fury starring on the bill.