The women’s side secured a famous 80-70 win in front of a raucous crowd at the University of Essex Sports Arena to seal their spot in the last two of the Betty Codona Trophy.
They will now face defending champions London Lions in the hotly anticipated final which will be staged at the 15,000 capacity Utilita Arena in Birmingham on Sunday.
The showpiece will also be broadcast to thousands more on Sky Sports Arena.
Saturday’s win over the Manchester Giants saw Tyra Whitehead and Kat Tudor put in strong performances to get their side over the line and confirm the Rebel’s place in their first ever final.
Head coach Ashley Cookson said: “We are happy to get through a tough opponent in Manchester, making us earn the spot in the final.
“I’m proud of this team’s achievement making a Women’s British Basketball final for the first time in Essex Rebels history.
“We knew from day one we have the talent in the building to make it to every game available to play in, so now we need to bring our A game on a national stage.”
The Rebels will head into Sunday’s final as underdogs, with the London Lions dominating WBBL in recent years.
But Cookson hopes the players will rise to the big occasion and cause an upset to claim the Rebels’ first piece of silverware.
He added: “London are the obvious favourite with investment made in their team and winning at the Eurocup level, but I’m a sucker for an underdog story and we will embrace the challenge on Sunday.”
Supporters interested in travelling to Birmingham on the Rebels' supporters bus should email essexrebels@essex.ac.uk.
Tickets for the final are available here.