Matchroom Sport chairman Eddie Hearn said: “I can’t quite believe this is happening but let me tell you, it’s happening.
“Weeks of negotiations have led to one of the biggest moments in British boxing – these two born rivals will do battle in an epic match up that has absolutely everything.
“Ever since they both turned professional, people talked about this moment and now is the time to see the historic rivalry continue. I want to thank DAZN for all their support in making this mega fight – roll on 8 October.”
Eubank Jr, 32 (32-2, 23 knockouts), is a former two-time IBO super-middleweight champion and secured an impressive points win over Liam Williams at the Motorpoint Arena Cardiff in his previous fight, in which he knocked down the Welshman four times.
Meanwhile, Conor Benn (21-0, 14 KOs) has predominantly fought at welterweight and holds the WBA Continental belt in that division. Last time out, the 25-year-old stopped Chris van Heerden in the second round.
The fighters’ fathers fought one another in 1990 and 1993, with Eubank winning their first bout via stoppage before the pair drew in their rematch.