The welterweight matchup — originally scheduled for UFC London in March — was officially announced by the promotion on Thursday along with a number of other fights. It will notably open up the main card of the event headlined by a middleweight contest between former champion Robert Whittaker and Darren Till.
Dalby last competed in September at UFC Copenhagen where he outpointed Alex Oliveira to get the win on his return to the promotion. In total, the 35-year-old is undefeated in his last five outings with four of those being victories.
Roberts, meanwhile, last competed in November at UFC Moscow where he bounced back from a two-fight losing skid with an impressive knockout victory over Zelim Imadaev.
Both fighters will undoubtedly be looking to keep the momentum going when they eventually clash next month.