The producer and the 'Eastenders' actress - who are close friends - will celebrate turning 59 and 40 respectively at a 'Music & Magic Ball' which will feature a special show by magician Dynamo and a DJ set by Birthday Girl Patsy, who has just took a break from her role as Bianca in the BBC One soap.
There will also be performances from 12 of the biggest-selling soul musicians of all-time, including 'You Got The Love' singer Candi Staton, legendary Motown act Martha Reeves & The Vandellas and Peabo Bryson - who sang on Disney tracks 'A Whole New World (Aladdin's Theme)' and 'Beauty and the Beast'.
The joint Celebration takes place at London's Grand Connaught Rooms and will also feature live and silent auctions of music memorabilia which will raise money for the 'Me&Dee Charity' which aims to provide children fighting life-threatening conditions with special moments.
The charity - which was set up in 2006 by Maria Hanson and which Gest is a patron of - also runs a comfort pack scheme which supplies kids and teenagers battling cancer with gifts and toys.
Speaking about the party, former 'I'm a celebrity... Get Me Out of Here!' star Gest said: ''At this stage in life it's not so much about celebrating a birthday as getting together with great friends and helping a good cause. Patsy and I have been friends for years and we thought if we could help put a smile on the faces of some people who are less fortunate than us that makes this whole evening worthwhile.''