Paul's upcoming fight against Rahman Jr will take place at Madison Square Garden on August 6.
Amanda Serrano will face Brenda Carabajal in the co-main event, while the YouTuber comes up against a legitimate boxer for the first time.
This is comfortably the toughest test of his career to date and if he wins, WBC president Sulaiman has revealed (via Twitter) how he will be rewarded:
"Coming on August 6, Jake Paul will take on Hasim Rahman Jr. Winning this fight will earn him a World Boxing Council ranking."
Paul has five wins as a professional boxer, though the first two of these came against fellow YouTuber AnEsonGib and ex-NBA star Nate Robinson.
He went on to knockout renowned wrestler Ben Askren, who made his name by winning world titles in MMA.
The 25-year-old is coming off consecutive victories over ex-UFC world champion Tyron Woodley. Their second meeting was ended via a clinical knockout.
Paul was originally scheduled to fight Tyson Fury's brother - Tommy Fury - instead of Rahman Jr. This bout had to be called off after the Brit was banned from entering the United States due to his alleged links with suspected crime boss Daniel Kinahan.
Rahman Jr, who has sparred Paul in the past, agreed to step in as a last-minute replacement. He is coming into the fight on the back of a stoppage loss back in April, but he does have a 12-1 record as a pro.
Paul clearly has grander plans beyond Rahman Jr, as he is eyeing a fight against Conor McGregor.
The Irishman is reportedly in talks to face Floyd Mayweather Jr in a big-money rematch worth around £130m.
The YouTuber has argued that McGregor should face him, as it would be "way more competitive":
"Me vs. Conor is a way bigger fight," said Paul when appearing on The DAZN Boxing Show.
"Floyd is old, and we've already seen that product.
"We know it's just a money play if they fight. Me vs Conor is way more competitive, there'll be way more s*** talked, way more entertaining, and it's the one that everyone really wants."