The TOWIE star revealed last year that his beloved mum had been diagnosed with myeloid leukaemia and her only chance of being cured would come from a stem cell transplant.
Bobby launched a campaign with blood cancer charity Anthony Nolan to raise awareness, help his mother and others in the same situation - and all his campaigning has paid off as a donor has been found for Kym.
A thrilled Bobby said: "I can never thank my mum's donor enough. This amazing person hasn't just saved my mum, they've saved me too. My mum is my best friend and she's everything to me.
"Without the work of Anthony Nolan, and the hero who donated their stem cells, there would be little hope, it doesn't bear thinking about. I genuinely feel like there is an Angel on this earth, I hope one day I can thank them in person."
Kym, a dental receptionist, had the transplant procedure done at UCL Hospital and is now back home recovering.
Several celebrities had helped spread the word about Anthony Nolan including TOWIE stars of past and present such as Lauren Goodger, Mark Wright, Sam Faiers and Lauren Pope. Help also came from Geordie Shore and Made In Chelsea stars as well as the likes of Katie Price and Denise Van Outen.
More than 3,100 people joined the Anthony Nolan stem cell register in just one week after Bobby made his initial appeal, which marked an incredible 750% rise from the same period last year.
Bobby's mum is now recovering but he's said he'll keep championing the charity and spreading awareness.
"When my mum was diagnosed, I felt helpless," he said. "All I could do apart from being there for mum was to try to raise awareness of the Anthony Nolan register, particularly to young people who are much more likely to go onto donate and save a life. I was bowled over by how many people signed up as a result of #SaveBobbysMum, and it's amazing to think that any of these wonderful people could go on to save the life of someone just like my mum."
Bobby threw a gala in aid of Anthony Nolan last year, that was featured on TOWIE. Stars of the show offered auction prizes including tickets to a McBusted concert and a chance to meet Lindsay Lohan. The night ended with that famous Full Monty-style striptease by the boys.
Ann O'Leary, Head of Register Development at Anthony Nolan, said: "We're over the moon that we've been able to find a suitable donor for Kym and that she's now on the road to recovery.
"We're so grateful to Bobby for spreading the word about the simple but life-changing act of donating stem cells and setting such an incredible and selfless example to young people.
"It's our goal to save the life of everyone who needs a transplant so it's wonderful that Bobby is now carrying on the fight against blood cancer and urging even more people to come forward and support the work of Anthony Nolan – in particular young men."
For more information or to register as a donor visit www.anthonynolan.org.