Manuwa replaces Antonio Rogerio Nogueira, who was originally scheduled to fight Gustafsson but withdrew last week due to injury. The new bout, which UFC officials confirmed on Tuesday, will headline the Fox Sports event.
Gustafsson (15-2) will close out 2013 with just one appearance, a unanimous decision loss to light heavyweight champion Jon Jones at UFC 165 in September. The five-round title fight was an instant classic and potential fight of the year.
Fighting out of Stockholm, Gustafsson is ranked the No. 2 light heavyweight in the world, according to ESPN.com.
Manuwa (14-0) is coming off last month's second-round TKO victory over Ryan Jimmo at UFC Fight Night 30. The 33-year-old Brit has finished all 14 opponents he's faced in his professional career, which began in 2008.
There was speculation Gustafsson might face UFC heavyweight Daniel Cormier (13-0), who is expected to make his light heavyweight debut in his next appearance. UFC president Dana White said on Tuesday, however, that Cormier was not considered.
"Cormier has never made it to 205 before," White said. "This fight is going to be over in London. Manuwa is undefeated. He's a big, nasty striker and he's a light heavyweight."